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 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD: releng/10.0/sys/fs/tmpfs/tmpfs_subr.c 255008 2013-08-28 22:12:56Z ken $");
38
39 #include <sys/param.h>
40 #include <sys/fnv_hash.h>
41 #include <sys/lock.h>
42 #include <sys/namei.h>
43 #include <sys/priv.h>
44 #include <sys/proc.h>
45 #include <sys/rwlock.h>
46 #include <sys/stat.h>
47 #include <sys/systm.h>
48 #include <sys/sysctl.h>
49 #include <sys/vnode.h>
50 #include <sys/vmmeter.h>
51
52 #include <vm/vm.h>
53 #include <vm/vm_param.h>
54 #include <vm/vm_object.h>
55 #include <vm/vm_page.h>
56 #include <vm/vm_pageout.h>
57 #include <vm/vm_pager.h>
58 #include <vm/vm_extern.h>
59
60 #include <fs/tmpfs/tmpfs.h>
61 #include <fs/tmpfs/tmpfs_fifoops.h>
62 #include <fs/tmpfs/tmpfs_vnops.h>
63
64 struct tmpfs_dir_cursor {
65 struct tmpfs_dirent *tdc_current;
66 struct tmpfs_dirent *tdc_tree;
67 };
68
69 SYSCTL_NODE(_vfs, OID_AUTO, tmpfs, CTLFLAG_RW, 0, "tmpfs file system");
70
71 static long tmpfs_pages_reserved = TMPFS_PAGES_MINRESERVED;
72
73 static int
74 sysctl_mem_reserved(SYSCTL_HANDLER_ARGS)
75 {
76 int error;
77 long pages, bytes;
78
79 pages = *(long *)arg1;
80 bytes = pages * PAGE_SIZE;
81
82 error = sysctl_handle_long(oidp, &bytes, 0, req);
83 if (error || !req->newptr)
84 return (error);
85
86 pages = bytes / PAGE_SIZE;
87 if (pages < TMPFS_PAGES_MINRESERVED)
88 return (EINVAL);
89
90 *(long *)arg1 = pages;
91 return (0);
92 }
93
94 SYSCTL_PROC(_vfs_tmpfs, OID_AUTO, memory_reserved, CTLTYPE_LONG|CTLFLAG_RW,
95 &tmpfs_pages_reserved, 0, sysctl_mem_reserved, "L",
96 "Amount of available memory and swap below which tmpfs growth stops");
97
98 static __inline int tmpfs_dirtree_cmp(struct tmpfs_dirent *a,
99 struct tmpfs_dirent *b);
100 RB_PROTOTYPE_STATIC(tmpfs_dir, tmpfs_dirent, uh.td_entries, tmpfs_dirtree_cmp);
101
102 size_t
103 tmpfs_mem_avail(void)
104 {
105 vm_ooffset_t avail;
106
107 avail = swap_pager_avail + cnt.v_free_count + cnt.v_cache_count -
108 tmpfs_pages_reserved;
109 if (__predict_false(avail < 0))
110 avail = 0;
111 return (avail);
112 }
113
114 size_t
115 tmpfs_pages_used(struct tmpfs_mount *tmp)
116 {
117 const size_t node_size = sizeof(struct tmpfs_node) +
118 sizeof(struct tmpfs_dirent);
119 size_t meta_pages;
120
121 meta_pages = howmany((uintmax_t)tmp->tm_nodes_inuse * node_size,
122 PAGE_SIZE);
123 return (meta_pages + tmp->tm_pages_used);
124 }
125
126 static size_t
127 tmpfs_pages_check_avail(struct tmpfs_mount *tmp, size_t req_pages)
128 {
129 if (tmpfs_mem_avail() < req_pages)
130 return (0);
131
132 if (tmp->tm_pages_max != SIZE_MAX &&
133 tmp->tm_pages_max < req_pages + tmpfs_pages_used(tmp))
134 return (0);
135
136 return (1);
137 }
138
139 /* --------------------------------------------------------------------- */
140
141 /*
142 * Allocates a new node of type 'type' inside the 'tmp' mount point, with
143 * its owner set to 'uid', its group to 'gid' and its mode set to 'mode',
144 * using the credentials of the process 'p'.
145 *
146 * If the node type is set to 'VDIR', then the parent parameter must point
147 * to the parent directory of the node being created. It may only be NULL
148 * while allocating the root node.
149 *
150 * If the node type is set to 'VBLK' or 'VCHR', then the rdev parameter
151 * specifies the device the node represents.
152 *
153 * If the node type is set to 'VLNK', then the parameter target specifies
154 * the file name of the target file for the symbolic link that is being
155 * created.
156 *
157 * Note that new nodes are retrieved from the available list if it has
158 * items or, if it is empty, from the node pool as long as there is enough
159 * space to create them.
160 *
161 * Returns zero on success or an appropriate error code on failure.
162 */
163 int
164 tmpfs_alloc_node(struct tmpfs_mount *tmp, enum vtype type,
165 uid_t uid, gid_t gid, mode_t mode, struct tmpfs_node *parent,
166 char *target, dev_t rdev, struct tmpfs_node **node)
167 {
168 struct tmpfs_node *nnode;
169 vm_object_t obj;
170
171 /* If the root directory of the 'tmp' file system is not yet
172 * allocated, this must be the request to do it. */
173 MPASS(IMPLIES(tmp->tm_root == NULL, parent == NULL && type == VDIR));
174
175 MPASS(IFF(type == VLNK, target != NULL));
176 MPASS(IFF(type == VBLK || type == VCHR, rdev != VNOVAL));
177
178 if (tmp->tm_nodes_inuse >= tmp->tm_nodes_max)
179 return (ENOSPC);
180 if (tmpfs_pages_check_avail(tmp, 1) == 0)
181 return (ENOSPC);
182
183 nnode = (struct tmpfs_node *)uma_zalloc_arg(
184 tmp->tm_node_pool, tmp, M_WAITOK);
185
186 /* Generic initialization. */
187 nnode->tn_type = type;
188 vfs_timestamp(&nnode->tn_atime);
189 nnode->tn_birthtime = nnode->tn_ctime = nnode->tn_mtime =
190 nnode->tn_atime;
191 nnode->tn_uid = uid;
192 nnode->tn_gid = gid;
193 nnode->tn_mode = mode;
194 nnode->tn_id = alloc_unr(tmp->tm_ino_unr);
195
196 /* Type-specific initialization. */
197 switch (nnode->tn_type) {
198 case VBLK:
199 case VCHR:
200 nnode->tn_rdev = rdev;
201 break;
202
203 case VDIR:
204 RB_INIT(&nnode->tn_dir.tn_dirhead);
205 LIST_INIT(&nnode->tn_dir.tn_dupindex);
206 MPASS(parent != nnode);
207 MPASS(IMPLIES(parent == NULL, tmp->tm_root == NULL));
208 nnode->tn_dir.tn_parent = (parent == NULL) ? nnode : parent;
209 nnode->tn_dir.tn_readdir_lastn = 0;
210 nnode->tn_dir.tn_readdir_lastp = NULL;
211 nnode->tn_links++;
212 TMPFS_NODE_LOCK(nnode->tn_dir.tn_parent);
213 nnode->tn_dir.tn_parent->tn_links++;
214 TMPFS_NODE_UNLOCK(nnode->tn_dir.tn_parent);
215 break;
216
217 case VFIFO:
218 /* FALLTHROUGH */
219 case VSOCK:
220 break;
221
222 case VLNK:
223 MPASS(strlen(target) < MAXPATHLEN);
224 nnode->tn_size = strlen(target);
225 nnode->tn_link = malloc(nnode->tn_size, M_TMPFSNAME,
226 M_WAITOK);
227 memcpy(nnode->tn_link, target, nnode->tn_size);
228 break;
229
230 case VREG:
231 obj = nnode->tn_reg.tn_aobj =
232 vm_pager_allocate(OBJT_SWAP, NULL, 0, VM_PROT_DEFAULT, 0,
233 NULL /* XXXKIB - tmpfs needs swap reservation */);
234 VM_OBJECT_WLOCK(obj);
235 /* OBJ_TMPFS is set together with the setting of vp->v_object */
236 vm_object_set_flag(obj, OBJ_NOSPLIT);
237 vm_object_clear_flag(obj, OBJ_ONEMAPPING);
238 VM_OBJECT_WUNLOCK(obj);
239 break;
240
241 default:
242 panic("tmpfs_alloc_node: type %p %d", nnode, (int)nnode->tn_type);
243 }
244
245 TMPFS_LOCK(tmp);
246 LIST_INSERT_HEAD(&tmp->tm_nodes_used, nnode, tn_entries);
247 tmp->tm_nodes_inuse++;
248 TMPFS_UNLOCK(tmp);
249
250 *node = nnode;
251 return 0;
252 }
253
254 /* --------------------------------------------------------------------- */
255
256 /*
257 * Destroys the node pointed to by node from the file system 'tmp'.
258 * If the node does not belong to the given mount point, the results are
259 * unpredicted.
260 *
261 * If the node references a directory; no entries are allowed because
262 * their removal could need a recursive algorithm, something forbidden in
263 * kernel space. Furthermore, there is not need to provide such
264 * functionality (recursive removal) because the only primitives offered
265 * to the user are the removal of empty directories and the deletion of
266 * individual files.
267 *
268 * Note that nodes are not really deleted; in fact, when a node has been
269 * allocated, it cannot be deleted during the whole life of the file
270 * system. Instead, they are moved to the available list and remain there
271 * until reused.
272 */
273 void
274 tmpfs_free_node(struct tmpfs_mount *tmp, struct tmpfs_node *node)
275 {
276 vm_object_t uobj;
277
278 #ifdef INVARIANTS
279 TMPFS_NODE_LOCK(node);
280 MPASS(node->tn_vnode == NULL);
281 MPASS((node->tn_vpstate & TMPFS_VNODE_ALLOCATING) == 0);
282 TMPFS_NODE_UNLOCK(node);
283 #endif
284
285 TMPFS_LOCK(tmp);
286 LIST_REMOVE(node, tn_entries);
287 tmp->tm_nodes_inuse--;
288 TMPFS_UNLOCK(tmp);
289
290 switch (node->tn_type) {
291 case VNON:
292 /* Do not do anything. VNON is provided to let the
293 * allocation routine clean itself easily by avoiding
294 * duplicating code in it. */
295 /* FALLTHROUGH */
296 case VBLK:
297 /* FALLTHROUGH */
298 case VCHR:
299 /* FALLTHROUGH */
300 case VDIR:
301 /* FALLTHROUGH */
302 case VFIFO:
303 /* FALLTHROUGH */
304 case VSOCK:
305 break;
306
307 case VLNK:
308 free(node->tn_link, M_TMPFSNAME);
309 break;
310
311 case VREG:
312 uobj = node->tn_reg.tn_aobj;
313 if (uobj != NULL) {
314 TMPFS_LOCK(tmp);
315 tmp->tm_pages_used -= uobj->size;
316 TMPFS_UNLOCK(tmp);
317 KASSERT((uobj->flags & OBJ_TMPFS) == 0,
318 ("leaked OBJ_TMPFS node %p vm_obj %p", node, uobj));
319 vm_object_deallocate(uobj);
320 }
321 break;
322
323 default:
324 panic("tmpfs_free_node: type %p %d", node, (int)node->tn_type);
325 }
326
327 free_unr(tmp->tm_ino_unr, node->tn_id);
328 uma_zfree(tmp->tm_node_pool, node);
329 }
330
331 /* --------------------------------------------------------------------- */
332
333 static __inline uint32_t
334 tmpfs_dirent_hash(const char *name, u_int len)
335 {
336 uint32_t hash;
337
338 hash = fnv_32_buf(name, len, FNV1_32_INIT + len) & TMPFS_DIRCOOKIE_MASK;
339 #ifdef TMPFS_DEBUG_DIRCOOKIE_DUP
340 hash &= 0xf;
341 #endif
342 if (hash < TMPFS_DIRCOOKIE_MIN)
343 hash += TMPFS_DIRCOOKIE_MIN;
344
345 return (hash);
346 }
347
348 static __inline off_t
349 tmpfs_dirent_cookie(struct tmpfs_dirent *de)
350 {
351 MPASS(de->td_cookie >= TMPFS_DIRCOOKIE_MIN);
352
353 return (de->td_cookie);
354 }
355
356 static __inline boolean_t
357 tmpfs_dirent_dup(struct tmpfs_dirent *de)
358 {
359 return ((de->td_cookie & TMPFS_DIRCOOKIE_DUP) != 0);
360 }
361
362 static __inline boolean_t
363 tmpfs_dirent_duphead(struct tmpfs_dirent *de)
364 {
365 return ((de->td_cookie & TMPFS_DIRCOOKIE_DUPHEAD) != 0);
366 }
367
368 void
369 tmpfs_dirent_init(struct tmpfs_dirent *de, const char *name, u_int namelen)
370 {
371 de->td_hash = de->td_cookie = tmpfs_dirent_hash(name, namelen);
372 memcpy(de->ud.td_name, name, namelen);
373 de->td_namelen = namelen;
374 }
375
376 /*
377 * Allocates a new directory entry for the node node with a name of name.
378 * The new directory entry is returned in *de.
379 *
380 * The link count of node is increased by one to reflect the new object
381 * referencing it.
382 *
383 * Returns zero on success or an appropriate error code on failure.
384 */
385 int
386 tmpfs_alloc_dirent(struct tmpfs_mount *tmp, struct tmpfs_node *node,
387 const char *name, u_int len, struct tmpfs_dirent **de)
388 {
389 struct tmpfs_dirent *nde;
390
391 nde = uma_zalloc(tmp->tm_dirent_pool, M_WAITOK);
392 nde->td_node = node;
393 if (name != NULL) {
394 nde->ud.td_name = malloc(len, M_TMPFSNAME, M_WAITOK);
395 tmpfs_dirent_init(nde, name, len);
396 } else
397 nde->td_namelen = 0;
398 if (node != NULL)
399 node->tn_links++;
400
401 *de = nde;
402
403 return 0;
404 }
405
406 /* --------------------------------------------------------------------- */
407
408 /*
409 * Frees a directory entry. It is the caller's responsibility to destroy
410 * the node referenced by it if needed.
411 *
412 * The link count of node is decreased by one to reflect the removal of an
413 * object that referenced it. This only happens if 'node_exists' is true;
414 * otherwise the function will not access the node referred to by the
415 * directory entry, as it may already have been released from the outside.
416 */
417 void
418 tmpfs_free_dirent(struct tmpfs_mount *tmp, struct tmpfs_dirent *de)
419 {
420 struct tmpfs_node *node;
421
422 node = de->td_node;
423 if (node != NULL) {
424 MPASS(node->tn_links > 0);
425 node->tn_links--;
426 }
427 if (!tmpfs_dirent_duphead(de) && de->ud.td_name != NULL)
428 free(de->ud.td_name, M_TMPFSNAME);
429 uma_zfree(tmp->tm_dirent_pool, de);
430 }
431
432 /* --------------------------------------------------------------------- */
433
434 void
435 tmpfs_destroy_vobject(struct vnode *vp, vm_object_t obj)
436 {
437
438 if (vp->v_type != VREG || obj == NULL)
439 return;
440
441 VM_OBJECT_WLOCK(obj);
442 VI_LOCK(vp);
443 vm_object_clear_flag(obj, OBJ_TMPFS);
444 obj->un_pager.swp.swp_tmpfs = NULL;
445 VI_UNLOCK(vp);
446 VM_OBJECT_WUNLOCK(obj);
447 }
448
449 /*
450 * Need to clear v_object for insmntque failure.
451 */
452 static void
453 tmpfs_insmntque_dtr(struct vnode *vp, void *dtr_arg)
454 {
455
456 tmpfs_destroy_vobject(vp, vp->v_object);
457 vp->v_object = NULL;
458 vp->v_data = NULL;
459 vp->v_op = &dead_vnodeops;
460 vgone(vp);
461 vput(vp);
462 }
463
464 /*
465 * Allocates a new vnode for the node node or returns a new reference to
466 * an existing one if the node had already a vnode referencing it. The
467 * resulting locked vnode is returned in *vpp.
468 *
469 * Returns zero on success or an appropriate error code on failure.
470 */
471 int
472 tmpfs_alloc_vp(struct mount *mp, struct tmpfs_node *node, int lkflag,
473 struct vnode **vpp)
474 {
475 struct vnode *vp;
476 vm_object_t object;
477 int error;
478
479 error = 0;
480 loop:
481 TMPFS_NODE_LOCK(node);
482 loop1:
483 if ((vp = node->tn_vnode) != NULL) {
484 MPASS((node->tn_vpstate & TMPFS_VNODE_DOOMED) == 0);
485 VI_LOCK(vp);
486 if ((node->tn_type == VDIR && node->tn_dir.tn_parent == NULL) ||
487 ((vp->v_iflag & VI_DOOMED) != 0 &&
488 (lkflag & LK_NOWAIT) != 0)) {
489 VI_UNLOCK(vp);
490 TMPFS_NODE_UNLOCK(node);
491 error = ENOENT;
492 vp = NULL;
493 goto out;
494 }
495 if ((vp->v_iflag & VI_DOOMED) != 0) {
496 VI_UNLOCK(vp);
497 node->tn_vpstate |= TMPFS_VNODE_WRECLAIM;
498 while ((node->tn_vpstate & TMPFS_VNODE_WRECLAIM) != 0) {
499 msleep(&node->tn_vnode, TMPFS_NODE_MTX(node),
500 0, "tmpfsE", 0);
501 }
502 goto loop1;
503 }
504 TMPFS_NODE_UNLOCK(node);
505 error = vget(vp, lkflag | LK_INTERLOCK, curthread);
506 if (error == ENOENT)
507 goto loop;
508 if (error != 0) {
509 vp = NULL;
510 goto out;
511 }
512
513 /*
514 * Make sure the vnode is still there after
515 * getting the interlock to avoid racing a free.
516 */
517 if (node->tn_vnode == NULL || node->tn_vnode != vp) {
518 vput(vp);
519 goto loop;
520 }
521
522 goto out;
523 }
524
525 if ((node->tn_vpstate & TMPFS_VNODE_DOOMED) ||
526 (node->tn_type == VDIR && node->tn_dir.tn_parent == NULL)) {
527 TMPFS_NODE_UNLOCK(node);
528 error = ENOENT;
529 vp = NULL;
530 goto out;
531 }
532
533 /*
534 * otherwise lock the vp list while we call getnewvnode
535 * since that can block.
536 */
537 if (node->tn_vpstate & TMPFS_VNODE_ALLOCATING) {
538 node->tn_vpstate |= TMPFS_VNODE_WANT;
539 error = msleep((caddr_t) &node->tn_vpstate,
540 TMPFS_NODE_MTX(node), PDROP | PCATCH,
541 "tmpfs_alloc_vp", 0);
542 if (error)
543 return error;
544
545 goto loop;
546 } else
547 node->tn_vpstate |= TMPFS_VNODE_ALLOCATING;
548
549 TMPFS_NODE_UNLOCK(node);
550
551 /* Get a new vnode and associate it with our node. */
552 error = getnewvnode("tmpfs", mp, &tmpfs_vnodeop_entries, &vp);
553 if (error != 0)
554 goto unlock;
555 MPASS(vp != NULL);
556
557 (void) vn_lock(vp, lkflag | LK_RETRY);
558
559 vp->v_data = node;
560 vp->v_type = node->tn_type;
561
562 /* Type-specific initialization. */
563 switch (node->tn_type) {
564 case VBLK:
565 /* FALLTHROUGH */
566 case VCHR:
567 /* FALLTHROUGH */
568 case VLNK:
569 /* FALLTHROUGH */
570 case VSOCK:
571 break;
572 case VFIFO:
573 vp->v_op = &tmpfs_fifoop_entries;
574 break;
575 case VREG:
576 object = node->tn_reg.tn_aobj;
577 VM_OBJECT_WLOCK(object);
578 VI_LOCK(vp);
579 KASSERT(vp->v_object == NULL, ("Not NULL v_object in tmpfs"));
580 vp->v_object = object;
581 object->un_pager.swp.swp_tmpfs = vp;
582 vm_object_set_flag(object, OBJ_TMPFS);
583 VI_UNLOCK(vp);
584 VM_OBJECT_WUNLOCK(object);
585 break;
586 case VDIR:
587 MPASS(node->tn_dir.tn_parent != NULL);
588 if (node->tn_dir.tn_parent == node)
589 vp->v_vflag |= VV_ROOT;
590 break;
591
592 default:
593 panic("tmpfs_alloc_vp: type %p %d", node, (int)node->tn_type);
594 }
595
596 error = insmntque1(vp, mp, tmpfs_insmntque_dtr, NULL);
597 if (error)
598 vp = NULL;
599
600 unlock:
601 TMPFS_NODE_LOCK(node);
602
603 MPASS(node->tn_vpstate & TMPFS_VNODE_ALLOCATING);
604 node->tn_vpstate &= ~TMPFS_VNODE_ALLOCATING;
605 node->tn_vnode = vp;
606
607 if (node->tn_vpstate & TMPFS_VNODE_WANT) {
608 node->tn_vpstate &= ~TMPFS_VNODE_WANT;
609 TMPFS_NODE_UNLOCK(node);
610 wakeup((caddr_t) &node->tn_vpstate);
611 } else
612 TMPFS_NODE_UNLOCK(node);
613
614 out:
615 *vpp = vp;
616
617 #ifdef INVARIANTS
618 if (error == 0) {
619 MPASS(*vpp != NULL && VOP_ISLOCKED(*vpp));
620 TMPFS_NODE_LOCK(node);
621 MPASS(*vpp == node->tn_vnode);
622 TMPFS_NODE_UNLOCK(node);
623 }
624 #endif
625
626 return error;
627 }
628
629 /* --------------------------------------------------------------------- */
630
631 /*
632 * Destroys the association between the vnode vp and the node it
633 * references.
634 */
635 void
636 tmpfs_free_vp(struct vnode *vp)
637 {
638 struct tmpfs_node *node;
639
640 node = VP_TO_TMPFS_NODE(vp);
641
642 mtx_assert(TMPFS_NODE_MTX(node), MA_OWNED);
643 node->tn_vnode = NULL;
644 if ((node->tn_vpstate & TMPFS_VNODE_WRECLAIM) != 0)
645 wakeup(&node->tn_vnode);
646 node->tn_vpstate &= ~TMPFS_VNODE_WRECLAIM;
647 vp->v_data = NULL;
648 }
649
650 /* --------------------------------------------------------------------- */
651
652 /*
653 * Allocates a new file of type 'type' and adds it to the parent directory
654 * 'dvp'; this addition is done using the component name given in 'cnp'.
655 * The ownership of the new file is automatically assigned based on the
656 * credentials of the caller (through 'cnp'), the group is set based on
657 * the parent directory and the mode is determined from the 'vap' argument.
658 * If successful, *vpp holds a vnode to the newly created file and zero
659 * is returned. Otherwise *vpp is NULL and the function returns an
660 * appropriate error code.
661 */
662 int
663 tmpfs_alloc_file(struct vnode *dvp, struct vnode **vpp, struct vattr *vap,
664 struct componentname *cnp, char *target)
665 {
666 int error;
667 struct tmpfs_dirent *de;
668 struct tmpfs_mount *tmp;
669 struct tmpfs_node *dnode;
670 struct tmpfs_node *node;
671 struct tmpfs_node *parent;
672
673 MPASS(VOP_ISLOCKED(dvp));
674 MPASS(cnp->cn_flags & HASBUF);
675
676 tmp = VFS_TO_TMPFS(dvp->v_mount);
677 dnode = VP_TO_TMPFS_DIR(dvp);
678 *vpp = NULL;
679
680 /* If the entry we are creating is a directory, we cannot overflow
681 * the number of links of its parent, because it will get a new
682 * link. */
683 if (vap->va_type == VDIR) {
684 /* Ensure that we do not overflow the maximum number of links
685 * imposed by the system. */
686 MPASS(dnode->tn_links <= LINK_MAX);
687 if (dnode->tn_links == LINK_MAX) {
688 error = EMLINK;
689 goto out;
690 }
691
692 parent = dnode;
693 MPASS(parent != NULL);
694 } else
695 parent = NULL;
696
697 /* Allocate a node that represents the new file. */
698 error = tmpfs_alloc_node(tmp, vap->va_type, cnp->cn_cred->cr_uid,
699 dnode->tn_gid, vap->va_mode, parent, target, vap->va_rdev, &node);
700 if (error != 0)
701 goto out;
702
703 /* Allocate a directory entry that points to the new file. */
704 error = tmpfs_alloc_dirent(tmp, node, cnp->cn_nameptr, cnp->cn_namelen,
705 &de);
706 if (error != 0) {
707 tmpfs_free_node(tmp, node);
708 goto out;
709 }
710
711 /* Allocate a vnode for the new file. */
712 error = tmpfs_alloc_vp(dvp->v_mount, node, LK_EXCLUSIVE, vpp);
713 if (error != 0) {
714 tmpfs_free_dirent(tmp, de);
715 tmpfs_free_node(tmp, node);
716 goto out;
717 }
718
719 /* Now that all required items are allocated, we can proceed to
720 * insert the new node into the directory, an operation that
721 * cannot fail. */
722 if (cnp->cn_flags & ISWHITEOUT)
723 tmpfs_dir_whiteout_remove(dvp, cnp);
724 tmpfs_dir_attach(dvp, de);
725
726 out:
727
728 return error;
729 }
730
731 /* --------------------------------------------------------------------- */
732
733 static struct tmpfs_dirent *
734 tmpfs_dir_first(struct tmpfs_node *dnode, struct tmpfs_dir_cursor *dc)
735 {
736 struct tmpfs_dirent *de;
737
738 de = RB_MIN(tmpfs_dir, &dnode->tn_dir.tn_dirhead);
739 dc->tdc_tree = de;
740 if (de != NULL && tmpfs_dirent_duphead(de))
741 de = LIST_FIRST(&de->ud.td_duphead);
742 dc->tdc_current = de;
743
744 return (dc->tdc_current);
745 }
746
747 static struct tmpfs_dirent *
748 tmpfs_dir_next(struct tmpfs_node *dnode, struct tmpfs_dir_cursor *dc)
749 {
750 struct tmpfs_dirent *de;
751
752 MPASS(dc->tdc_tree != NULL);
753 if (tmpfs_dirent_dup(dc->tdc_current)) {
754 dc->tdc_current = LIST_NEXT(dc->tdc_current, uh.td_dup.entries);
755 if (dc->tdc_current != NULL)
756 return (dc->tdc_current);
757 }
758 dc->tdc_tree = dc->tdc_current = RB_NEXT(tmpfs_dir,
759 &dnode->tn_dir.tn_dirhead, dc->tdc_tree);
760 if ((de = dc->tdc_current) != NULL && tmpfs_dirent_duphead(de)) {
761 dc->tdc_current = LIST_FIRST(&de->ud.td_duphead);
762 MPASS(dc->tdc_current != NULL);
763 }
764
765 return (dc->tdc_current);
766 }
767
768 /* Lookup directory entry in RB-Tree. Function may return duphead entry. */
769 static struct tmpfs_dirent *
770 tmpfs_dir_xlookup_hash(struct tmpfs_node *dnode, uint32_t hash)
771 {
772 struct tmpfs_dirent *de, dekey;
773
774 dekey.td_hash = hash;
775 de = RB_FIND(tmpfs_dir, &dnode->tn_dir.tn_dirhead, &dekey);
776 return (de);
777 }
778
779 /* Lookup directory entry by cookie, initialize directory cursor accordingly. */
780 static struct tmpfs_dirent *
781 tmpfs_dir_lookup_cookie(struct tmpfs_node *node, off_t cookie,
782 struct tmpfs_dir_cursor *dc)
783 {
784 struct tmpfs_dir *dirhead = &node->tn_dir.tn_dirhead;
785 struct tmpfs_dirent *de, dekey;
786
787 MPASS(cookie >= TMPFS_DIRCOOKIE_MIN);
788
789 if (cookie == node->tn_dir.tn_readdir_lastn &&
790 (de = node->tn_dir.tn_readdir_lastp) != NULL) {
791 /* Protect against possible race, tn_readdir_last[pn]
792 * may be updated with only shared vnode lock held. */
793 if (cookie == tmpfs_dirent_cookie(de))
794 goto out;
795 }
796
797 if ((cookie & TMPFS_DIRCOOKIE_DUP) != 0) {
798 LIST_FOREACH(de, &node->tn_dir.tn_dupindex,
799 uh.td_dup.index_entries) {
800 MPASS(tmpfs_dirent_dup(de));
801 if (de->td_cookie == cookie)
802 goto out;
803 /* dupindex list is sorted. */
804 if (de->td_cookie < cookie) {
805 de = NULL;
806 goto out;
807 }
808 }
809 MPASS(de == NULL);
810 goto out;
811 }
812
813 MPASS((cookie & TMPFS_DIRCOOKIE_MASK) == cookie);
814 dekey.td_hash = cookie;
815 /* Recover if direntry for cookie was removed */
816 de = RB_NFIND(tmpfs_dir, dirhead, &dekey);
817 dc->tdc_tree = de;
818 dc->tdc_current = de;
819 if (de != NULL && tmpfs_dirent_duphead(de)) {
820 dc->tdc_current = LIST_FIRST(&de->ud.td_duphead);
821 MPASS(dc->tdc_current != NULL);
822 }
823 return (dc->tdc_current);
824
825 out:
826 dc->tdc_tree = de;
827 dc->tdc_current = de;
828 if (de != NULL && tmpfs_dirent_dup(de))
829 dc->tdc_tree = tmpfs_dir_xlookup_hash(node,
830 de->td_hash);
831 return (dc->tdc_current);
832 }
833
834 /*
835 * Looks for a directory entry in the directory represented by node.
836 * 'cnp' describes the name of the entry to look for. Note that the .
837 * and .. components are not allowed as they do not physically exist
838 * within directories.
839 *
840 * Returns a pointer to the entry when found, otherwise NULL.
841 */
842 struct tmpfs_dirent *
843 tmpfs_dir_lookup(struct tmpfs_node *node, struct tmpfs_node *f,
844 struct componentname *cnp)
845 {
846 struct tmpfs_dir_duphead *duphead;
847 struct tmpfs_dirent *de;
848 uint32_t hash;
849
850 MPASS(IMPLIES(cnp->cn_namelen == 1, cnp->cn_nameptr[0] != '.'));
851 MPASS(IMPLIES(cnp->cn_namelen == 2, !(cnp->cn_nameptr[0] == '.' &&
852 cnp->cn_nameptr[1] == '.')));
853 TMPFS_VALIDATE_DIR(node);
854
855 hash = tmpfs_dirent_hash(cnp->cn_nameptr, cnp->cn_namelen);
856 de = tmpfs_dir_xlookup_hash(node, hash);
857 if (de != NULL && tmpfs_dirent_duphead(de)) {
858 duphead = &de->ud.td_duphead;
859 LIST_FOREACH(de, duphead, uh.td_dup.entries) {
860 if (TMPFS_DIRENT_MATCHES(de, cnp->cn_nameptr,
861 cnp->cn_namelen))
862 break;
863 }
864 } else if (de != NULL) {
865 if (!TMPFS_DIRENT_MATCHES(de, cnp->cn_nameptr,
866 cnp->cn_namelen))
867 de = NULL;
868 }
869 if (de != NULL && f != NULL && de->td_node != f)
870 de = NULL;
871
872 return (de);
873 }
874
875 /*
876 * Attach duplicate-cookie directory entry nde to dnode and insert to dupindex
877 * list, allocate new cookie value.
878 */
879 static void
880 tmpfs_dir_attach_dup(struct tmpfs_node *dnode,
881 struct tmpfs_dir_duphead *duphead, struct tmpfs_dirent *nde)
882 {
883 struct tmpfs_dir_duphead *dupindex;
884 struct tmpfs_dirent *de, *pde;
885
886 dupindex = &dnode->tn_dir.tn_dupindex;
887 de = LIST_FIRST(dupindex);
888 if (de == NULL || de->td_cookie < TMPFS_DIRCOOKIE_DUP_MAX) {
889 if (de == NULL)
890 nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MIN;
891 else
892 nde->td_cookie = de->td_cookie + 1;
893 MPASS(tmpfs_dirent_dup(nde));
894 LIST_INSERT_HEAD(dupindex, nde, uh.td_dup.index_entries);
895 LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries);
896 return;
897 }
898
899 /*
900 * Cookie numbers are near exhaustion. Scan dupindex list for unused
901 * numbers. dupindex list is sorted in descending order. Keep it so
902 * after inserting nde.
903 */
904 while (1) {
905 pde = de;
906 de = LIST_NEXT(de, uh.td_dup.index_entries);
907 if (de == NULL && pde->td_cookie != TMPFS_DIRCOOKIE_DUP_MIN) {
908 /*
909 * Last element of the index doesn't have minimal cookie
910 * value, use it.
911 */
912 nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MIN;
913 LIST_INSERT_AFTER(pde, nde, uh.td_dup.index_entries);
914 LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries);
915 return;
916 } else if (de == NULL) {
917 /*
918 * We are so lucky have 2^30 hash duplicates in single
919 * directory :) Return largest possible cookie value.
920 * It should be fine except possible issues with
921 * VOP_READDIR restart.
922 */
923 nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MAX;
924 LIST_INSERT_HEAD(dupindex, nde,
925 uh.td_dup.index_entries);
926 LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries);
927 return;
928 }
929 if (de->td_cookie + 1 == pde->td_cookie ||
930 de->td_cookie >= TMPFS_DIRCOOKIE_DUP_MAX)
931 continue; /* No hole or invalid cookie. */
932 nde->td_cookie = de->td_cookie + 1;
933 MPASS(tmpfs_dirent_dup(nde));
934 MPASS(pde->td_cookie > nde->td_cookie);
935 MPASS(nde->td_cookie > de->td_cookie);
936 LIST_INSERT_BEFORE(de, nde, uh.td_dup.index_entries);
937 LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries);
938 return;
939 };
940 }
941
942 /*
943 * Attaches the directory entry de to the directory represented by vp.
944 * Note that this does not change the link count of the node pointed by
945 * the directory entry, as this is done by tmpfs_alloc_dirent.
946 */
947 void
948 tmpfs_dir_attach(struct vnode *vp, struct tmpfs_dirent *de)
949 {
950 struct tmpfs_node *dnode;
951 struct tmpfs_dirent *xde, *nde;
952
953 ASSERT_VOP_ELOCKED(vp, __func__);
954 MPASS(de->td_namelen > 0);
955 MPASS(de->td_hash >= TMPFS_DIRCOOKIE_MIN);
956 MPASS(de->td_cookie == de->td_hash);
957
958 dnode = VP_TO_TMPFS_DIR(vp);
959 dnode->tn_dir.tn_readdir_lastn = 0;
960 dnode->tn_dir.tn_readdir_lastp = NULL;
961
962 MPASS(!tmpfs_dirent_dup(de));
963 xde = RB_INSERT(tmpfs_dir, &dnode->tn_dir.tn_dirhead, de);
964 if (xde != NULL && tmpfs_dirent_duphead(xde))
965 tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, de);
966 else if (xde != NULL) {
967 /*
968 * Allocate new duphead. Swap xde with duphead to avoid
969 * adding/removing elements with the same hash.
970 */
971 MPASS(!tmpfs_dirent_dup(xde));
972 tmpfs_alloc_dirent(VFS_TO_TMPFS(vp->v_mount), NULL, NULL, 0,
973 &nde);
974 /* *nde = *xde; XXX gcc 4.2.1 may generate invalid code. */
975 memcpy(nde, xde, sizeof(*xde));
976 xde->td_cookie |= TMPFS_DIRCOOKIE_DUPHEAD;
977 LIST_INIT(&xde->ud.td_duphead);
978 xde->td_namelen = 0;
979 xde->td_node = NULL;
980 tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, nde);
981 tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, de);
982 }
983 dnode->tn_size += sizeof(struct tmpfs_dirent);
984 dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \
985 TMPFS_NODE_MODIFIED;
986 }
987
988 /* --------------------------------------------------------------------- */
989
990 /*
991 * Detaches the directory entry de from the directory represented by vp.
992 * Note that this does not change the link count of the node pointed by
993 * the directory entry, as this is done by tmpfs_free_dirent.
994 */
995 void
996 tmpfs_dir_detach(struct vnode *vp, struct tmpfs_dirent *de)
997 {
998 struct tmpfs_mount *tmp;
999 struct tmpfs_dir *head;
1000 struct tmpfs_node *dnode;
1001 struct tmpfs_dirent *xde;
1002
1003 ASSERT_VOP_ELOCKED(vp, __func__);
1004
1005 dnode = VP_TO_TMPFS_DIR(vp);
1006 head = &dnode->tn_dir.tn_dirhead;
1007 dnode->tn_dir.tn_readdir_lastn = 0;
1008 dnode->tn_dir.tn_readdir_lastp = NULL;
1009
1010 if (tmpfs_dirent_dup(de)) {
1011 /* Remove duphead if de was last entry. */
1012 if (LIST_NEXT(de, uh.td_dup.entries) == NULL) {
1013 xde = tmpfs_dir_xlookup_hash(dnode, de->td_hash);
1014 MPASS(tmpfs_dirent_duphead(xde));
1015 } else
1016 xde = NULL;
1017 LIST_REMOVE(de, uh.td_dup.entries);
1018 LIST_REMOVE(de, uh.td_dup.index_entries);
1019 if (xde != NULL) {
1020 if (LIST_EMPTY(&xde->ud.td_duphead)) {
1021 RB_REMOVE(tmpfs_dir, head, xde);
1022 tmp = VFS_TO_TMPFS(vp->v_mount);
1023 MPASS(xde->td_node == NULL);
1024 tmpfs_free_dirent(tmp, xde);
1025 }
1026 }
1027 } else
1028 RB_REMOVE(tmpfs_dir, head, de);
1029
1030 dnode->tn_size -= sizeof(struct tmpfs_dirent);
1031 dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \
1032 TMPFS_NODE_MODIFIED;
1033 }
1034
1035 void
1036 tmpfs_dir_destroy(struct tmpfs_mount *tmp, struct tmpfs_node *dnode)
1037 {
1038 struct tmpfs_dirent *de, *dde, *nde;
1039
1040 RB_FOREACH_SAFE(de, tmpfs_dir, &dnode->tn_dir.tn_dirhead, nde) {
1041 RB_REMOVE(tmpfs_dir, &dnode->tn_dir.tn_dirhead, de);
1042 /* Node may already be destroyed. */
1043 de->td_node = NULL;
1044 if (tmpfs_dirent_duphead(de)) {
1045 while ((dde = LIST_FIRST(&de->ud.td_duphead)) != NULL) {
1046 LIST_REMOVE(dde, uh.td_dup.entries);
1047 dde->td_node = NULL;
1048 tmpfs_free_dirent(tmp, dde);
1049 }
1050 }
1051 tmpfs_free_dirent(tmp, de);
1052 }
1053 }
1054
1055 /* --------------------------------------------------------------------- */
1056
1057 /*
1058 * Helper function for tmpfs_readdir. Creates a '.' entry for the given
1059 * directory and returns it in the uio space. The function returns 0
1060 * on success, -1 if there was not enough space in the uio structure to
1061 * hold the directory entry or an appropriate error code if another
1062 * error happens.
1063 */
1064 static int
1065 tmpfs_dir_getdotdent(struct tmpfs_node *node, struct uio *uio)
1066 {
1067 int error;
1068 struct dirent dent;
1069
1070 TMPFS_VALIDATE_DIR(node);
1071 MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOT);
1072
1073 dent.d_fileno = node->tn_id;
1074 dent.d_type = DT_DIR;
1075 dent.d_namlen = 1;
1076 dent.d_name[0] = '.';
1077 dent.d_name[1] = '\0';
1078 dent.d_reclen = GENERIC_DIRSIZ(&dent);
1079
1080 if (dent.d_reclen > uio->uio_resid)
1081 error = EJUSTRETURN;
1082 else
1083 error = uiomove(&dent, dent.d_reclen, uio);
1084
1085 node->tn_status |= TMPFS_NODE_ACCESSED;
1086
1087 return error;
1088 }
1089
1090 /* --------------------------------------------------------------------- */
1091
1092 /*
1093 * Helper function for tmpfs_readdir. Creates a '..' entry for the given
1094 * directory and returns it in the uio space. The function returns 0
1095 * on success, -1 if there was not enough space in the uio structure to
1096 * hold the directory entry or an appropriate error code if another
1097 * error happens.
1098 */
1099 static int
1100 tmpfs_dir_getdotdotdent(struct tmpfs_node *node, struct uio *uio)
1101 {
1102 int error;
1103 struct dirent dent;
1104
1105 TMPFS_VALIDATE_DIR(node);
1106 MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT);
1107
1108 /*
1109 * Return ENOENT if the current node is already removed.
1110 */
1111 TMPFS_ASSERT_LOCKED(node);
1112 if (node->tn_dir.tn_parent == NULL) {
1113 return (ENOENT);
1114 }
1115
1116 TMPFS_NODE_LOCK(node->tn_dir.tn_parent);
1117 dent.d_fileno = node->tn_dir.tn_parent->tn_id;
1118 TMPFS_NODE_UNLOCK(node->tn_dir.tn_parent);
1119
1120 dent.d_type = DT_DIR;
1121 dent.d_namlen = 2;
1122 dent.d_name[0] = '.';
1123 dent.d_name[1] = '.';
1124 dent.d_name[2] = '\0';
1125 dent.d_reclen = GENERIC_DIRSIZ(&dent);
1126
1127 if (dent.d_reclen > uio->uio_resid)
1128 error = EJUSTRETURN;
1129 else
1130 error = uiomove(&dent, dent.d_reclen, uio);
1131
1132 node->tn_status |= TMPFS_NODE_ACCESSED;
1133
1134 return error;
1135 }
1136
1137 /* --------------------------------------------------------------------- */
1138
1139 /*
1140 * Helper function for tmpfs_readdir. Returns as much directory entries
1141 * as can fit in the uio space. The read starts at uio->uio_offset.
1142 * The function returns 0 on success, -1 if there was not enough space
1143 * in the uio structure to hold the directory entry or an appropriate
1144 * error code if another error happens.
1145 */
1146 int
1147 tmpfs_dir_getdents(struct tmpfs_node *node, struct uio *uio, int cnt,
1148 u_long *cookies, int *ncookies)
1149 {
1150 struct tmpfs_dir_cursor dc;
1151 struct tmpfs_dirent *de;
1152 off_t off;
1153 int error;
1154
1155 TMPFS_VALIDATE_DIR(node);
1156
1157 off = 0;
1158 switch (uio->uio_offset) {
1159 case TMPFS_DIRCOOKIE_DOT:
1160 error = tmpfs_dir_getdotdent(node, uio);
1161 if (error != 0)
1162 return (error);
1163 uio->uio_offset = TMPFS_DIRCOOKIE_DOTDOT;
1164 if (cnt != 0)
1165 cookies[(*ncookies)++] = off = uio->uio_offset;
1166 case TMPFS_DIRCOOKIE_DOTDOT:
1167 error = tmpfs_dir_getdotdotdent(node, uio);
1168 if (error != 0)
1169 return (error);
1170 de = tmpfs_dir_first(node, &dc);
1171 if (de == NULL)
1172 uio->uio_offset = TMPFS_DIRCOOKIE_EOF;
1173 else
1174 uio->uio_offset = tmpfs_dirent_cookie(de);
1175 if (cnt != 0)
1176 cookies[(*ncookies)++] = off = uio->uio_offset;
1177 if (de == NULL)
1178 return (0);
1179 break;
1180 case TMPFS_DIRCOOKIE_EOF:
1181 return (0);
1182 default:
1183 de = tmpfs_dir_lookup_cookie(node, uio->uio_offset, &dc);
1184 if (de == NULL)
1185 return (EINVAL);
1186 if (cnt != 0)
1187 off = tmpfs_dirent_cookie(de);
1188 }
1189
1190 /* Read as much entries as possible; i.e., until we reach the end of
1191 * the directory or we exhaust uio space. */
1192 do {
1193 struct dirent d;
1194
1195 /* Create a dirent structure representing the current
1196 * tmpfs_node and fill it. */
1197 if (de->td_node == NULL) {
1198 d.d_fileno = 1;
1199 d.d_type = DT_WHT;
1200 } else {
1201 d.d_fileno = de->td_node->tn_id;
1202 switch (de->td_node->tn_type) {
1203 case VBLK:
1204 d.d_type = DT_BLK;
1205 break;
1206
1207 case VCHR:
1208 d.d_type = DT_CHR;
1209 break;
1210
1211 case VDIR:
1212 d.d_type = DT_DIR;
1213 break;
1214
1215 case VFIFO:
1216 d.d_type = DT_FIFO;
1217 break;
1218
1219 case VLNK:
1220 d.d_type = DT_LNK;
1221 break;
1222
1223 case VREG:
1224 d.d_type = DT_REG;
1225 break;
1226
1227 case VSOCK:
1228 d.d_type = DT_SOCK;
1229 break;
1230
1231 default:
1232 panic("tmpfs_dir_getdents: type %p %d",
1233 de->td_node, (int)de->td_node->tn_type);
1234 }
1235 }
1236 d.d_namlen = de->td_namelen;
1237 MPASS(de->td_namelen < sizeof(d.d_name));
1238 (void)memcpy(d.d_name, de->ud.td_name, de->td_namelen);
1239 d.d_name[de->td_namelen] = '\0';
1240 d.d_reclen = GENERIC_DIRSIZ(&d);
1241
1242 /* Stop reading if the directory entry we are treating is
1243 * bigger than the amount of data that can be returned. */
1244 if (d.d_reclen > uio->uio_resid) {
1245 error = EJUSTRETURN;
1246 break;
1247 }
1248
1249 /* Copy the new dirent structure into the output buffer and
1250 * advance pointers. */
1251 error = uiomove(&d, d.d_reclen, uio);
1252 if (error == 0) {
1253 de = tmpfs_dir_next(node, &dc);
1254 if (cnt != 0) {
1255 if (de == NULL)
1256 off = TMPFS_DIRCOOKIE_EOF;
1257 else
1258 off = tmpfs_dirent_cookie(de);
1259 MPASS(*ncookies < cnt);
1260 cookies[(*ncookies)++] = off;
1261 }
1262 }
1263 } while (error == 0 && uio->uio_resid > 0 && de != NULL);
1264
1265 /* Update the offset and cache. */
1266 if (cnt == 0) {
1267 if (de == NULL)
1268 off = TMPFS_DIRCOOKIE_EOF;
1269 else
1270 off = tmpfs_dirent_cookie(de);
1271 }
1272
1273 uio->uio_offset = off;
1274 node->tn_dir.tn_readdir_lastn = off;
1275 node->tn_dir.tn_readdir_lastp = de;
1276
1277 node->tn_status |= TMPFS_NODE_ACCESSED;
1278 return error;
1279 }
1280
1281 int
1282 tmpfs_dir_whiteout_add(struct vnode *dvp, struct componentname *cnp)
1283 {
1284 struct tmpfs_dirent *de;
1285 int error;
1286
1287 error = tmpfs_alloc_dirent(VFS_TO_TMPFS(dvp->v_mount), NULL,
1288 cnp->cn_nameptr, cnp->cn_namelen, &de);
1289 if (error != 0)
1290 return (error);
1291 tmpfs_dir_attach(dvp, de);
1292 return (0);
1293 }
1294
1295 void
1296 tmpfs_dir_whiteout_remove(struct vnode *dvp, struct componentname *cnp)
1297 {
1298 struct tmpfs_dirent *de;
1299
1300 de = tmpfs_dir_lookup(VP_TO_TMPFS_DIR(dvp), NULL, cnp);
1301 MPASS(de != NULL && de->td_node == NULL);
1302 tmpfs_dir_detach(dvp, de);
1303 tmpfs_free_dirent(VFS_TO_TMPFS(dvp->v_mount), de);
1304 }
1305
1306 /* --------------------------------------------------------------------- */
1307
1308 /*
1309 * Resizes the aobj associated with the regular file pointed to by 'vp' to the
1310 * size 'newsize'. 'vp' must point to a vnode that represents a regular file.
1311 * 'newsize' must be positive.
1312 *
1313 * Returns zero on success or an appropriate error code on failure.
1314 */
1315 int
1316 tmpfs_reg_resize(struct vnode *vp, off_t newsize, boolean_t ignerr)
1317 {
1318 struct tmpfs_mount *tmp;
1319 struct tmpfs_node *node;
1320 vm_object_t uobj;
1321 vm_page_t m, ma[1];
1322 vm_pindex_t idx, newpages, oldpages;
1323 off_t oldsize;
1324 int base, rv;
1325
1326 MPASS(vp->v_type == VREG);
1327 MPASS(newsize >= 0);
1328
1329 node = VP_TO_TMPFS_NODE(vp);
1330 uobj = node->tn_reg.tn_aobj;
1331 tmp = VFS_TO_TMPFS(vp->v_mount);
1332
1333 /*
1334 * Convert the old and new sizes to the number of pages needed to
1335 * store them. It may happen that we do not need to do anything
1336 * because the last allocated page can accommodate the change on
1337 * its own.
1338 */
1339 oldsize = node->tn_size;
1340 oldpages = OFF_TO_IDX(oldsize + PAGE_MASK);
1341 MPASS(oldpages == uobj->size);
1342 newpages = OFF_TO_IDX(newsize + PAGE_MASK);
1343 if (newpages > oldpages &&
1344 tmpfs_pages_check_avail(tmp, newpages - oldpages) == 0)
1345 return (ENOSPC);
1346
1347 VM_OBJECT_WLOCK(uobj);
1348 if (newsize < oldsize) {
1349 /*
1350 * Zero the truncated part of the last page.
1351 */
1352 base = newsize & PAGE_MASK;
1353 if (base != 0) {
1354 idx = OFF_TO_IDX(newsize);
1355 retry:
1356 m = vm_page_lookup(uobj, idx);
1357 if (m != NULL) {
1358 if (vm_page_sleep_if_busy(m, "tmfssz"))
1359 goto retry;
1360 MPASS(m->valid == VM_PAGE_BITS_ALL);
1361 } else if (vm_pager_has_page(uobj, idx, NULL, NULL)) {
1362 m = vm_page_alloc(uobj, idx, VM_ALLOC_NORMAL);
1363 if (m == NULL) {
1364 VM_OBJECT_WUNLOCK(uobj);
1365 VM_WAIT;
1366 VM_OBJECT_WLOCK(uobj);
1367 goto retry;
1368 } else if (m->valid != VM_PAGE_BITS_ALL) {
1369 ma[0] = m;
1370 rv = vm_pager_get_pages(uobj, ma, 1, 0);
1371 m = vm_page_lookup(uobj, idx);
1372 } else
1373 /* A cached page was reactivated. */
1374 rv = VM_PAGER_OK;
1375 vm_page_lock(m);
1376 if (rv == VM_PAGER_OK) {
1377 vm_page_deactivate(m);
1378 vm_page_unlock(m);
1379 vm_page_xunbusy(m);
1380 } else {
1381 vm_page_free(m);
1382 vm_page_unlock(m);
1383 if (ignerr)
1384 m = NULL;
1385 else {
1386 VM_OBJECT_WUNLOCK(uobj);
1387 return (EIO);
1388 }
1389 }
1390 }
1391 if (m != NULL) {
1392 pmap_zero_page_area(m, base, PAGE_SIZE - base);
1393 vm_page_dirty(m);
1394 vm_pager_page_unswapped(m);
1395 }
1396 }
1397
1398 /*
1399 * Release any swap space and free any whole pages.
1400 */
1401 if (newpages < oldpages) {
1402 swap_pager_freespace(uobj, newpages, oldpages -
1403 newpages);
1404 vm_object_page_remove(uobj, newpages, 0, 0);
1405 }
1406 }
1407 uobj->size = newpages;
1408 VM_OBJECT_WUNLOCK(uobj);
1409
1410 TMPFS_LOCK(tmp);
1411 tmp->tm_pages_used += (newpages - oldpages);
1412 TMPFS_UNLOCK(tmp);
1413
1414 node->tn_size = newsize;
1415 return (0);
1416 }
1417
1418 /* --------------------------------------------------------------------- */
1419
1420 /*
1421 * Change flags of the given vnode.
1422 * Caller should execute tmpfs_update on vp after a successful execution.
1423 * The vnode must be locked on entry and remain locked on exit.
1424 */
1425 int
1426 tmpfs_chflags(struct vnode *vp, u_long flags, struct ucred *cred,
1427 struct thread *p)
1428 {
1429 int error;
1430 struct tmpfs_node *node;
1431
1432 MPASS(VOP_ISLOCKED(vp));
1433
1434 node = VP_TO_TMPFS_NODE(vp);
1435
1436 if ((flags & ~(SF_APPEND | SF_ARCHIVED | SF_IMMUTABLE | SF_NOUNLINK |
1437 UF_APPEND | UF_ARCHIVE | UF_HIDDEN | UF_IMMUTABLE | UF_NODUMP |
1438 UF_NOUNLINK | UF_OFFLINE | UF_OPAQUE | UF_READONLY | UF_REPARSE |
1439 UF_SPARSE | UF_SYSTEM)) != 0)
1440 return (EOPNOTSUPP);
1441
1442 /* Disallow this operation if the file system is mounted read-only. */
1443 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1444 return EROFS;
1445
1446 /*
1447 * Callers may only modify the file flags on objects they
1448 * have VADMIN rights for.
1449 */
1450 if ((error = VOP_ACCESS(vp, VADMIN, cred, p)))
1451 return (error);
1452 /*
1453 * Unprivileged processes are not permitted to unset system
1454 * flags, or modify flags if any system flags are set.
1455 */
1456 if (!priv_check_cred(cred, PRIV_VFS_SYSFLAGS, 0)) {
1457 if (node->tn_flags &
1458 (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND)) {
1459 error = securelevel_gt(cred, 0);
1460 if (error)
1461 return (error);
1462 }
1463 } else {
1464 if (node->tn_flags &
1465 (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND) ||
1466 ((flags ^ node->tn_flags) & SF_SETTABLE))
1467 return (EPERM);
1468 }
1469 node->tn_flags = flags;
1470 node->tn_status |= TMPFS_NODE_CHANGED;
1471
1472 MPASS(VOP_ISLOCKED(vp));
1473
1474 return 0;
1475 }
1476
1477 /* --------------------------------------------------------------------- */
1478
1479 /*
1480 * Change access mode on the given vnode.
1481 * Caller should execute tmpfs_update on vp after a successful execution.
1482 * The vnode must be locked on entry and remain locked on exit.
1483 */
1484 int
1485 tmpfs_chmod(struct vnode *vp, mode_t mode, struct ucred *cred, struct thread *p)
1486 {
1487 int error;
1488 struct tmpfs_node *node;
1489
1490 MPASS(VOP_ISLOCKED(vp));
1491
1492 node = VP_TO_TMPFS_NODE(vp);
1493
1494 /* Disallow this operation if the file system is mounted read-only. */
1495 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1496 return EROFS;
1497
1498 /* Immutable or append-only files cannot be modified, either. */
1499 if (node->tn_flags & (IMMUTABLE | APPEND))
1500 return EPERM;
1501
1502 /*
1503 * To modify the permissions on a file, must possess VADMIN
1504 * for that file.
1505 */
1506 if ((error = VOP_ACCESS(vp, VADMIN, cred, p)))
1507 return (error);
1508
1509 /*
1510 * Privileged processes may set the sticky bit on non-directories,
1511 * as well as set the setgid bit on a file with a group that the
1512 * process is not a member of.
1513 */
1514 if (vp->v_type != VDIR && (mode & S_ISTXT)) {
1515 if (priv_check_cred(cred, PRIV_VFS_STICKYFILE, 0))
1516 return (EFTYPE);
1517 }
1518 if (!groupmember(node->tn_gid, cred) && (mode & S_ISGID)) {
1519 error = priv_check_cred(cred, PRIV_VFS_SETGID, 0);
1520 if (error)
1521 return (error);
1522 }
1523
1524
1525 node->tn_mode &= ~ALLPERMS;
1526 node->tn_mode |= mode & ALLPERMS;
1527
1528 node->tn_status |= TMPFS_NODE_CHANGED;
1529
1530 MPASS(VOP_ISLOCKED(vp));
1531
1532 return 0;
1533 }
1534
1535 /* --------------------------------------------------------------------- */
1536
1537 /*
1538 * Change ownership of the given vnode. At least one of uid or gid must
1539 * be different than VNOVAL. If one is set to that value, the attribute
1540 * is unchanged.
1541 * Caller should execute tmpfs_update on vp after a successful execution.
1542 * The vnode must be locked on entry and remain locked on exit.
1543 */
1544 int
1545 tmpfs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred,
1546 struct thread *p)
1547 {
1548 int error;
1549 struct tmpfs_node *node;
1550 uid_t ouid;
1551 gid_t ogid;
1552
1553 MPASS(VOP_ISLOCKED(vp));
1554
1555 node = VP_TO_TMPFS_NODE(vp);
1556
1557 /* Assign default values if they are unknown. */
1558 MPASS(uid != VNOVAL || gid != VNOVAL);
1559 if (uid == VNOVAL)
1560 uid = node->tn_uid;
1561 if (gid == VNOVAL)
1562 gid = node->tn_gid;
1563 MPASS(uid != VNOVAL && gid != VNOVAL);
1564
1565 /* Disallow this operation if the file system is mounted read-only. */
1566 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1567 return EROFS;
1568
1569 /* Immutable or append-only files cannot be modified, either. */
1570 if (node->tn_flags & (IMMUTABLE | APPEND))
1571 return EPERM;
1572
1573 /*
1574 * To modify the ownership of a file, must possess VADMIN for that
1575 * file.
1576 */
1577 if ((error = VOP_ACCESS(vp, VADMIN, cred, p)))
1578 return (error);
1579
1580 /*
1581 * To change the owner of a file, or change the group of a file to a
1582 * group of which we are not a member, the caller must have
1583 * privilege.
1584 */
1585 if ((uid != node->tn_uid ||
1586 (gid != node->tn_gid && !groupmember(gid, cred))) &&
1587 (error = priv_check_cred(cred, PRIV_VFS_CHOWN, 0)))
1588 return (error);
1589
1590 ogid = node->tn_gid;
1591 ouid = node->tn_uid;
1592
1593 node->tn_uid = uid;
1594 node->tn_gid = gid;
1595
1596 node->tn_status |= TMPFS_NODE_CHANGED;
1597
1598 if ((node->tn_mode & (S_ISUID | S_ISGID)) && (ouid != uid || ogid != gid)) {
1599 if (priv_check_cred(cred, PRIV_VFS_RETAINSUGID, 0))
1600 node->tn_mode &= ~(S_ISUID | S_ISGID);
1601 }
1602
1603 MPASS(VOP_ISLOCKED(vp));
1604
1605 return 0;
1606 }
1607
1608 /* --------------------------------------------------------------------- */
1609
1610 /*
1611 * Change size of the given vnode.
1612 * Caller should execute tmpfs_update on vp after a successful execution.
1613 * The vnode must be locked on entry and remain locked on exit.
1614 */
1615 int
1616 tmpfs_chsize(struct vnode *vp, u_quad_t size, struct ucred *cred,
1617 struct thread *p)
1618 {
1619 int error;
1620 struct tmpfs_node *node;
1621
1622 MPASS(VOP_ISLOCKED(vp));
1623
1624 node = VP_TO_TMPFS_NODE(vp);
1625
1626 /* Decide whether this is a valid operation based on the file type. */
1627 error = 0;
1628 switch (vp->v_type) {
1629 case VDIR:
1630 return EISDIR;
1631
1632 case VREG:
1633 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1634 return EROFS;
1635 break;
1636
1637 case VBLK:
1638 /* FALLTHROUGH */
1639 case VCHR:
1640 /* FALLTHROUGH */
1641 case VFIFO:
1642 /* Allow modifications of special files even if in the file
1643 * system is mounted read-only (we are not modifying the
1644 * files themselves, but the objects they represent). */
1645 return 0;
1646
1647 default:
1648 /* Anything else is unsupported. */
1649 return EOPNOTSUPP;
1650 }
1651
1652 /* Immutable or append-only files cannot be modified, either. */
1653 if (node->tn_flags & (IMMUTABLE | APPEND))
1654 return EPERM;
1655
1656 error = tmpfs_truncate(vp, size);
1657 /* tmpfs_truncate will raise the NOTE_EXTEND and NOTE_ATTRIB kevents
1658 * for us, as will update tn_status; no need to do that here. */
1659
1660 MPASS(VOP_ISLOCKED(vp));
1661
1662 return error;
1663 }
1664
1665 /* --------------------------------------------------------------------- */
1666
1667 /*
1668 * Change access and modification times of the given vnode.
1669 * Caller should execute tmpfs_update on vp after a successful execution.
1670 * The vnode must be locked on entry and remain locked on exit.
1671 */
1672 int
1673 tmpfs_chtimes(struct vnode *vp, struct timespec *atime, struct timespec *mtime,
1674 struct timespec *birthtime, int vaflags, struct ucred *cred, struct thread *l)
1675 {
1676 int error;
1677 struct tmpfs_node *node;
1678
1679 MPASS(VOP_ISLOCKED(vp));
1680
1681 node = VP_TO_TMPFS_NODE(vp);
1682
1683 /* Disallow this operation if the file system is mounted read-only. */
1684 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1685 return EROFS;
1686
1687 /* Immutable or append-only files cannot be modified, either. */
1688 if (node->tn_flags & (IMMUTABLE | APPEND))
1689 return EPERM;
1690
1691 /* Determine if the user have proper privilege to update time. */
1692 if (vaflags & VA_UTIMES_NULL) {
1693 error = VOP_ACCESS(vp, VADMIN, cred, l);
1694 if (error)
1695 error = VOP_ACCESS(vp, VWRITE, cred, l);
1696 } else
1697 error = VOP_ACCESS(vp, VADMIN, cred, l);
1698 if (error)
1699 return (error);
1700
1701 if (atime->tv_sec != VNOVAL && atime->tv_nsec != VNOVAL)
1702 node->tn_status |= TMPFS_NODE_ACCESSED;
1703
1704 if (mtime->tv_sec != VNOVAL && mtime->tv_nsec != VNOVAL)
1705 node->tn_status |= TMPFS_NODE_MODIFIED;
1706
1707 if (birthtime->tv_nsec != VNOVAL && birthtime->tv_nsec != VNOVAL)
1708 node->tn_status |= TMPFS_NODE_MODIFIED;
1709
1710 tmpfs_itimes(vp, atime, mtime);
1711
1712 if (birthtime->tv_nsec != VNOVAL && birthtime->tv_nsec != VNOVAL)
1713 node->tn_birthtime = *birthtime;
1714 MPASS(VOP_ISLOCKED(vp));
1715
1716 return 0;
1717 }
1718
1719 /* --------------------------------------------------------------------- */
1720 /* Sync timestamps */
1721 void
1722 tmpfs_itimes(struct vnode *vp, const struct timespec *acc,
1723 const struct timespec *mod)
1724 {
1725 struct tmpfs_node *node;
1726 struct timespec now;
1727
1728 node = VP_TO_TMPFS_NODE(vp);
1729
1730 if ((node->tn_status & (TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED |
1731 TMPFS_NODE_CHANGED)) == 0)
1732 return;
1733
1734 vfs_timestamp(&now);
1735 if (node->tn_status & TMPFS_NODE_ACCESSED) {
1736 if (acc == NULL)
1737 acc = &now;
1738 node->tn_atime = *acc;
1739 }
1740 if (node->tn_status & TMPFS_NODE_MODIFIED) {
1741 if (mod == NULL)
1742 mod = &now;
1743 node->tn_mtime = *mod;
1744 }
1745 if (node->tn_status & TMPFS_NODE_CHANGED) {
1746 node->tn_ctime = now;
1747 }
1748 node->tn_status &=
1749 ~(TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED | TMPFS_NODE_CHANGED);
1750 }
1751
1752 /* --------------------------------------------------------------------- */
1753
1754 void
1755 tmpfs_update(struct vnode *vp)
1756 {
1757
1758 tmpfs_itimes(vp, NULL, NULL);
1759 }
1760
1761 /* --------------------------------------------------------------------- */
1762
1763 int
1764 tmpfs_truncate(struct vnode *vp, off_t length)
1765 {
1766 int error;
1767 struct tmpfs_node *node;
1768
1769 node = VP_TO_TMPFS_NODE(vp);
1770
1771 if (length < 0) {
1772 error = EINVAL;
1773 goto out;
1774 }
1775
1776 if (node->tn_size == length) {
1777 error = 0;
1778 goto out;
1779 }
1780
1781 if (length > VFS_TO_TMPFS(vp->v_mount)->tm_maxfilesize)
1782 return (EFBIG);
1783
1784 error = tmpfs_reg_resize(vp, length, FALSE);
1785 if (error == 0) {
1786 node->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED;
1787 }
1788
1789 out:
1790 tmpfs_update(vp);
1791
1792 return error;
1793 }
1794
1795 static __inline int
1796 tmpfs_dirtree_cmp(struct tmpfs_dirent *a, struct tmpfs_dirent *b)
1797 {
1798 if (a->td_hash > b->td_hash)
1799 return (1);
1800 else if (a->td_hash < b->td_hash)
1801 return (-1);
1802 return (0);
1803 }
1804
1805 RB_GENERATE_STATIC(tmpfs_dir, tmpfs_dirent, uh.td_entries, tmpfs_dirtree_cmp);
Cache object: 7fa308b8161524a946fa9ce4696a74c4
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