xref: /dragonfly/sys/vfs/tmpfs/tmpfs_vnops.c (revision 77b0c609)
1 /*-
2  * Copyright (c) 2005, 2006 The NetBSD Foundation, Inc.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to The NetBSD Foundation
6  * by Julio M. Merino Vidal, developed as part of Google's Summer of Code
7  * 2005 program.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGE.
29  *
30  * $NetBSD: tmpfs_vnops.c,v 1.39 2007/07/23 15:41:01 jmmv Exp $
31  */
32 
33 /*
34  * tmpfs vnode interface.
35  */
36 
37 #include <sys/kernel.h>
38 #include <sys/kern_syscall.h>
39 #include <sys/param.h>
40 #include <sys/fcntl.h>
41 #include <sys/lockf.h>
42 #include <sys/priv.h>
43 #include <sys/proc.h>
44 #include <sys/resourcevar.h>
45 #include <sys/sched.h>
46 #include <sys/stat.h>
47 #include <sys/systm.h>
48 #include <sys/unistd.h>
49 #include <sys/vfsops.h>
50 #include <sys/vnode.h>
51 #include <sys/mountctl.h>
52 
53 #include <vm/vm.h>
54 #include <vm/vm_object.h>
55 #include <vm/vm_page.h>
56 #include <vm/vm_pager.h>
57 #include <vm/swap_pager.h>
58 
59 #include <sys/buf2.h>
60 
61 #include <vfs/fifofs/fifo.h>
62 #include <vfs/tmpfs/tmpfs_vnops.h>
63 #include <vfs/tmpfs/tmpfs.h>
64 
65 MALLOC_DECLARE(M_TMPFS);
66 
67 static void tmpfs_strategy_done(struct bio *bio);
68 
69 static __inline
70 void
71 tmpfs_knote(struct vnode *vp, int flags)
72 {
73 	if (flags)
74 		KNOTE(&vp->v_pollinfo.vpi_kqinfo.ki_note, flags);
75 }
76 
77 
78 /* --------------------------------------------------------------------- */
79 
80 static int
81 tmpfs_nresolve(struct vop_nresolve_args *v)
82 {
83 	struct vnode *dvp = v->a_dvp;
84 	struct vnode *vp = NULL;
85 	struct namecache *ncp = v->a_nch->ncp;
86 	struct tmpfs_node *tnode;
87 
88 	int error;
89 	struct tmpfs_dirent *de;
90 	struct tmpfs_node *dnode;
91 
92 	dnode = VP_TO_TMPFS_DIR(dvp);
93 
94 	de = tmpfs_dir_lookup(dnode, NULL, ncp);
95 	if (de == NULL) {
96 		error = ENOENT;
97 	} else {
98 		/*
99 		 * Allocate a vnode for the node we found.
100 		 */
101 		tnode = de->td_node;
102 		error = tmpfs_alloc_vp(dvp->v_mount, tnode,
103 				       LK_EXCLUSIVE | LK_RETRY, &vp);
104 		if (error)
105 			goto out;
106 		KKASSERT(vp);
107 	}
108 
109 out:
110 	/*
111 	 * Store the result of this lookup in the cache.  Avoid this if the
112 	 * request was for creation, as it does not improve timings on
113 	 * emprical tests.
114 	 */
115 	if (vp) {
116 		vn_unlock(vp);
117 		cache_setvp(v->a_nch, vp);
118 		vrele(vp);
119 	} else if (error == ENOENT) {
120 		cache_setvp(v->a_nch, NULL);
121 	}
122 	return error;
123 }
124 
125 static int
126 tmpfs_nlookupdotdot(struct vop_nlookupdotdot_args *v)
127 {
128 	struct vnode *dvp = v->a_dvp;
129 	struct vnode **vpp = v->a_vpp;
130 	struct tmpfs_node *dnode = VP_TO_TMPFS_NODE(dvp);
131 	struct ucred *cred = v->a_cred;
132 	int error;
133 
134 	*vpp = NULL;
135 	/* Check accessibility of requested node as a first step. */
136 	error = VOP_ACCESS(dvp, VEXEC, cred);
137 	if (error != 0)
138 		return error;
139 
140 	if (dnode->tn_dir.tn_parent != NULL) {
141 		/* Allocate a new vnode on the matching entry. */
142 		error = tmpfs_alloc_vp(dvp->v_mount, dnode->tn_dir.tn_parent,
143 		    LK_EXCLUSIVE | LK_RETRY, vpp);
144 
145 		if (*vpp)
146 			vn_unlock(*vpp);
147 	}
148 
149 	return (*vpp == NULL) ? ENOENT : 0;
150 }
151 
152 /* --------------------------------------------------------------------- */
153 
154 static int
155 tmpfs_ncreate(struct vop_ncreate_args *v)
156 {
157 	struct vnode *dvp = v->a_dvp;
158 	struct vnode **vpp = v->a_vpp;
159 	struct namecache *ncp = v->a_nch->ncp;
160 	struct vattr *vap = v->a_vap;
161 	struct ucred *cred = v->a_cred;
162 	int error;
163 
164 	KKASSERT(vap->va_type == VREG || vap->va_type == VSOCK);
165 
166 	error = tmpfs_alloc_file(dvp, vpp, vap, ncp, cred, NULL);
167 	if (error == 0) {
168 		cache_setunresolved(v->a_nch);
169 		cache_setvp(v->a_nch, *vpp);
170 		tmpfs_knote(dvp, NOTE_WRITE);
171 	}
172 
173 	return error;
174 }
175 /* --------------------------------------------------------------------- */
176 
177 static int
178 tmpfs_nmknod(struct vop_nmknod_args *v)
179 {
180 	struct vnode *dvp = v->a_dvp;
181 	struct vnode **vpp = v->a_vpp;
182 	struct namecache *ncp = v->a_nch->ncp;
183 	struct vattr *vap = v->a_vap;
184 	struct ucred *cred = v->a_cred;
185 	int error;
186 
187 	if (vap->va_type != VBLK && vap->va_type != VCHR &&
188 	    vap->va_type != VFIFO)
189 		return EINVAL;
190 
191 	error = tmpfs_alloc_file(dvp, vpp, vap, ncp, cred, NULL);
192 	if (error == 0) {
193 		cache_setunresolved(v->a_nch);
194 		cache_setvp(v->a_nch, *vpp);
195 		tmpfs_knote(dvp, NOTE_WRITE);
196 	}
197 
198 	return error;
199 }
200 
201 /* --------------------------------------------------------------------- */
202 
203 static int
204 tmpfs_open(struct vop_open_args *v)
205 {
206 	struct vnode *vp = v->a_vp;
207 	int mode = v->a_mode;
208 
209 	int error;
210 	struct tmpfs_node *node;
211 
212 	node = VP_TO_TMPFS_NODE(vp);
213 
214 #if 0
215 	/* The file is still active but all its names have been removed
216 	 * (e.g. by a "rmdir $(pwd)").  It cannot be opened any more as
217 	 * it is about to die. */
218 	if (node->tn_links < 1)
219 		return (ENOENT);
220 #endif
221 
222 	/* If the file is marked append-only, deny write requests. */
223 	if ((node->tn_flags & APPEND) &&
224 	    (mode & (FWRITE | O_APPEND)) == FWRITE) {
225 		error = EPERM;
226 	} else {
227 		return (vop_stdopen(v));
228 	}
229 	return error;
230 }
231 
232 /* --------------------------------------------------------------------- */
233 
234 static int
235 tmpfs_close(struct vop_close_args *v)
236 {
237 	struct vnode *vp = v->a_vp;
238 	struct tmpfs_node *node;
239 
240 	node = VP_TO_TMPFS_NODE(vp);
241 
242 	if (node->tn_links > 0) {
243 		/*
244 		 * Update node times.  No need to do it if the node has
245 		 * been deleted, because it will vanish after we return.
246 		 */
247 		tmpfs_update(vp);
248 	}
249 
250 	return vop_stdclose(v);
251 }
252 
253 /* --------------------------------------------------------------------- */
254 
255 int
256 tmpfs_access(struct vop_access_args *v)
257 {
258 	struct vnode *vp = v->a_vp;
259 	int error;
260 	struct tmpfs_node *node;
261 
262 	node = VP_TO_TMPFS_NODE(vp);
263 
264 	switch (vp->v_type) {
265 	case VDIR:
266 		/* FALLTHROUGH */
267 	case VLNK:
268 		/* FALLTHROUGH */
269 	case VREG:
270 		if ((v->a_mode & VWRITE) && (vp->v_mount->mnt_flag & MNT_RDONLY)) {
271 			error = EROFS;
272 			goto out;
273 		}
274 		break;
275 
276 	case VBLK:
277 		/* FALLTHROUGH */
278 	case VCHR:
279 		/* FALLTHROUGH */
280 	case VSOCK:
281 		/* FALLTHROUGH */
282 	case VFIFO:
283 		break;
284 
285 	default:
286 		error = EINVAL;
287 		goto out;
288 	}
289 
290 	if ((v->a_mode & VWRITE) && (node->tn_flags & IMMUTABLE)) {
291 		error = EPERM;
292 		goto out;
293 	}
294 
295 	error = vop_helper_access(v, node->tn_uid, node->tn_gid, node->tn_mode, 0);
296 
297 out:
298 
299 	return error;
300 }
301 
302 /* --------------------------------------------------------------------- */
303 
304 int
305 tmpfs_getattr(struct vop_getattr_args *v)
306 {
307 	struct vnode *vp = v->a_vp;
308 	struct vattr *vap = v->a_vap;
309 	struct tmpfs_node *node;
310 
311 	node = VP_TO_TMPFS_NODE(vp);
312 
313 	lwkt_gettoken(&vp->v_mount->mnt_token);
314 	tmpfs_update(vp);
315 
316 	vap->va_type = vp->v_type;
317 	vap->va_mode = node->tn_mode;
318 	vap->va_nlink = node->tn_links;
319 	vap->va_uid = node->tn_uid;
320 	vap->va_gid = node->tn_gid;
321 	vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
322 	vap->va_fileid = node->tn_id;
323 	vap->va_size = node->tn_size;
324 	vap->va_blocksize = PAGE_SIZE;
325 	vap->va_atime.tv_sec = node->tn_atime;
326 	vap->va_atime.tv_nsec = node->tn_atimensec;
327 	vap->va_mtime.tv_sec = node->tn_mtime;
328 	vap->va_mtime.tv_nsec = node->tn_mtimensec;
329 	vap->va_ctime.tv_sec = node->tn_ctime;
330 	vap->va_ctime.tv_nsec = node->tn_ctimensec;
331 	vap->va_gen = node->tn_gen;
332 	vap->va_flags = node->tn_flags;
333 	if (vp->v_type == VBLK || vp->v_type == VCHR)
334 	{
335 		vap->va_rmajor = umajor(node->tn_rdev);
336 		vap->va_rminor = uminor(node->tn_rdev);
337 	}
338 	vap->va_bytes = round_page(node->tn_size);
339 	vap->va_filerev = 0;
340 
341 	lwkt_reltoken(&vp->v_mount->mnt_token);
342 
343 	return 0;
344 }
345 
346 /* --------------------------------------------------------------------- */
347 
348 int
349 tmpfs_setattr(struct vop_setattr_args *v)
350 {
351 	struct vnode *vp = v->a_vp;
352 	struct vattr *vap = v->a_vap;
353 	struct ucred *cred = v->a_cred;
354 	struct tmpfs_node *node = VP_TO_TMPFS_NODE(vp);
355 	int error = 0;
356 	int kflags = 0;
357 
358 	if (error == 0 && (vap->va_flags != VNOVAL)) {
359 		error = tmpfs_chflags(vp, vap->va_flags, cred);
360 		kflags |= NOTE_ATTRIB;
361 	}
362 
363 	if (error == 0 && (vap->va_size != VNOVAL)) {
364 		if (vap->va_size > node->tn_size)
365 			kflags |= NOTE_WRITE | NOTE_EXTEND;
366 		else
367 			kflags |= NOTE_WRITE;
368 		error = tmpfs_chsize(vp, vap->va_size, cred);
369 	}
370 
371 	if (error == 0 && (vap->va_uid != (uid_t)VNOVAL ||
372 			   vap->va_gid != (gid_t)VNOVAL)) {
373 		error = tmpfs_chown(vp, vap->va_uid, vap->va_gid, cred);
374 		kflags |= NOTE_ATTRIB;
375 	}
376 
377 	if (error == 0 && (vap->va_mode != (mode_t)VNOVAL)) {
378 		error = tmpfs_chmod(vp, vap->va_mode, cred);
379 		kflags |= NOTE_ATTRIB;
380 	}
381 
382 	if (error == 0 && ((vap->va_atime.tv_sec != VNOVAL &&
383 	    vap->va_atime.tv_nsec != VNOVAL) ||
384 	    (vap->va_mtime.tv_sec != VNOVAL &&
385 	    vap->va_mtime.tv_nsec != VNOVAL) )) {
386 		error = tmpfs_chtimes(vp, &vap->va_atime, &vap->va_mtime,
387 				      vap->va_vaflags, cred);
388 		kflags |= NOTE_ATTRIB;
389 	}
390 
391 	/* Update the node times.  We give preference to the error codes
392 	 * generated by this function rather than the ones that may arise
393 	 * from tmpfs_update. */
394 	tmpfs_update(vp);
395 	tmpfs_knote(vp, kflags);
396 
397 	return error;
398 }
399 
400 /* --------------------------------------------------------------------- */
401 
402 /*
403  * fsync is usually a NOP, but we must take action when unmounting or
404  * when recycling.
405  */
406 static int
407 tmpfs_fsync(struct vop_fsync_args *v)
408 {
409 	struct tmpfs_node *node;
410 	struct vnode *vp = v->a_vp;
411 
412 	node = VP_TO_TMPFS_NODE(vp);
413 
414 	tmpfs_update(vp);
415 	if (vp->v_type == VREG) {
416 		if (vp->v_flag & VRECLAIMED) {
417 			if (node->tn_links == 0)
418 				tmpfs_truncate(vp, 0);
419 			else
420 				vfsync(v->a_vp, v->a_waitfor, 1, NULL, NULL);
421 		}
422 	}
423 	return 0;
424 }
425 
426 /* --------------------------------------------------------------------- */
427 
428 static int
429 tmpfs_read (struct vop_read_args *ap)
430 {
431 	struct buf *bp;
432 	struct vnode *vp = ap->a_vp;
433 	struct uio *uio = ap->a_uio;
434 	struct tmpfs_node *node;
435 	off_t base_offset;
436 	size_t offset;
437 	size_t len;
438 	int error;
439 
440 	error = 0;
441 	if (uio->uio_resid == 0) {
442 		return error;
443 	}
444 
445 	node = VP_TO_TMPFS_NODE(vp);
446 
447 	if (uio->uio_offset < 0)
448 		return (EINVAL);
449 	if (vp->v_type != VREG)
450 		return (EINVAL);
451 
452 	while (uio->uio_resid > 0 && uio->uio_offset < node->tn_size) {
453 		/*
454 		 * Use buffer cache I/O (via tmpfs_strategy)
455 		 */
456 		offset = (size_t)uio->uio_offset & BMASK;
457 		base_offset = (off_t)uio->uio_offset - offset;
458 		bp = getcacheblk(vp, base_offset, BSIZE, 0);
459 		if (bp == NULL) {
460 			lwkt_gettoken(&vp->v_mount->mnt_token);
461 			error = bread(vp, base_offset, BSIZE, &bp);
462 			if (error) {
463 				brelse(bp);
464 				lwkt_reltoken(&vp->v_mount->mnt_token);
465 				kprintf("tmpfs_read bread error %d\n", error);
466 				break;
467 			}
468 			lwkt_reltoken(&vp->v_mount->mnt_token);
469 		}
470 
471 		/*
472 		 * Figure out how many bytes we can actually copy this loop.
473 		 */
474 		len = BSIZE - offset;
475 		if (len > uio->uio_resid)
476 			len = uio->uio_resid;
477 		if (len > node->tn_size - uio->uio_offset)
478 			len = (size_t)(node->tn_size - uio->uio_offset);
479 
480 		error = uiomovebp(bp, (char *)bp->b_data + offset, len, uio);
481 		bqrelse(bp);
482 		if (error) {
483 			kprintf("tmpfs_read uiomove error %d\n", error);
484 			break;
485 		}
486 	}
487 
488 	TMPFS_NODE_LOCK(node);
489 	node->tn_status |= TMPFS_NODE_ACCESSED;
490 	TMPFS_NODE_UNLOCK(node);
491 
492 	return(error);
493 }
494 
495 static int
496 tmpfs_write (struct vop_write_args *ap)
497 {
498 	struct buf *bp;
499 	struct vnode *vp = ap->a_vp;
500 	struct uio *uio = ap->a_uio;
501 	struct thread *td = uio->uio_td;
502 	struct tmpfs_node *node;
503 	boolean_t extended;
504 	off_t oldsize;
505 	int error;
506 	off_t base_offset;
507 	size_t offset;
508 	size_t len;
509 	struct rlimit limit;
510 	int trivial = 0;
511 	int kflags = 0;
512 
513 	error = 0;
514 	if (uio->uio_resid == 0) {
515 		return error;
516 	}
517 
518 	node = VP_TO_TMPFS_NODE(vp);
519 
520 	if (vp->v_type != VREG)
521 		return (EINVAL);
522 
523 	lwkt_gettoken(&vp->v_mount->mnt_token);
524 
525 	oldsize = node->tn_size;
526 	if (ap->a_ioflag & IO_APPEND)
527 		uio->uio_offset = node->tn_size;
528 
529 	/*
530 	 * Check for illegal write offsets.
531 	 */
532 	if (uio->uio_offset + uio->uio_resid >
533 	  VFS_TO_TMPFS(vp->v_mount)->tm_maxfilesize) {
534 		lwkt_reltoken(&vp->v_mount->mnt_token);
535 		return (EFBIG);
536 	}
537 
538 	if (vp->v_type == VREG && td != NULL) {
539 		error = kern_getrlimit(RLIMIT_FSIZE, &limit);
540 		if (error != 0) {
541 			lwkt_reltoken(&vp->v_mount->mnt_token);
542 			return error;
543 		}
544 		if (uio->uio_offset + uio->uio_resid > limit.rlim_cur) {
545 			ksignal(td->td_proc, SIGXFSZ);
546 			lwkt_reltoken(&vp->v_mount->mnt_token);
547 			return (EFBIG);
548 		}
549 	}
550 
551 
552 	/*
553 	 * Extend the file's size if necessary
554 	 */
555 	extended = ((uio->uio_offset + uio->uio_resid) > node->tn_size);
556 
557 	while (uio->uio_resid > 0) {
558 		/*
559 		 * Use buffer cache I/O (via tmpfs_strategy)
560 		 */
561 		offset = (size_t)uio->uio_offset & BMASK;
562 		base_offset = (off_t)uio->uio_offset - offset;
563 		len = BSIZE - offset;
564 		if (len > uio->uio_resid)
565 			len = uio->uio_resid;
566 
567 		if ((uio->uio_offset + len) > node->tn_size) {
568 			trivial = (uio->uio_offset <= node->tn_size);
569 			error = tmpfs_reg_resize(vp, uio->uio_offset + len,  trivial);
570 			if (error)
571 				break;
572 		}
573 
574 		/*
575 		 * Read to fill in any gaps.  Theoretically we could
576 		 * optimize this if the write covers the entire buffer
577 		 * and is not a UIO_NOCOPY write, however this can lead
578 		 * to a security violation exposing random kernel memory
579 		 * (whatever junk was in the backing VM pages before).
580 		 *
581 		 * So just use bread() to do the right thing.
582 		 */
583 		error = bread(vp, base_offset, BSIZE, &bp);
584 		error = uiomovebp(bp, (char *)bp->b_data + offset, len, uio);
585 		if (error) {
586 			kprintf("tmpfs_write uiomove error %d\n", error);
587 			brelse(bp);
588 			break;
589 		}
590 
591 		if (uio->uio_offset > node->tn_size) {
592 			node->tn_size = uio->uio_offset;
593 			kflags |= NOTE_EXTEND;
594 		}
595 		kflags |= NOTE_WRITE;
596 
597 		/*
598 		 * Always try to flush the page if the request is coming
599 		 * from the pageout daemon (IO_ASYNC), else buwrite() the
600 		 * buffer.
601 		 *
602 		 * buwrite() dirties the underlying VM pages instead of
603 		 * dirtying the buffer, releasing the buffer as a clean
604 		 * buffer.  This allows tmpfs to use essentially all
605 		 * available memory to cache file data.  If we used bdwrite()
606 		 * the buffer cache would wind up flushing the data to
607 		 * swap too quickly.
608 		 */
609 		bp->b_flags |= B_AGE;
610 		if (ap->a_ioflag & IO_ASYNC) {
611 			bawrite(bp);
612 		} else {
613 			buwrite(bp);
614 		}
615 
616 		if (bp->b_error) {
617 			kprintf("tmpfs_write bwrite error %d\n", bp->b_error);
618 			break;
619 		}
620 	}
621 
622 	if (error) {
623 		if (extended) {
624 			(void)tmpfs_reg_resize(vp, oldsize, trivial);
625 			kflags &= ~NOTE_EXTEND;
626 		}
627 		goto done;
628 	}
629 
630 	/*
631 	 * Currently we don't set the mtime on files modified via mmap()
632 	 * because we can't tell the difference between those modifications
633 	 * and an attempt by the pageout daemon to flush tmpfs pages to
634 	 * swap.
635 	 *
636 	 * This is because in order to defer flushes as long as possible
637 	 * buwrite() works by marking the underlying VM pages dirty in
638 	 * order to be able to dispose of the buffer cache buffer without
639 	 * flushing it.
640 	 */
641 	TMPFS_NODE_LOCK(node);
642 	if (uio->uio_segflg != UIO_NOCOPY)
643 		node->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED;
644 	if (extended)
645 		node->tn_status |= TMPFS_NODE_CHANGED;
646 
647 	if (node->tn_mode & (S_ISUID | S_ISGID)) {
648 		if (priv_check_cred(ap->a_cred, PRIV_VFS_RETAINSUGID, 0))
649 			node->tn_mode &= ~(S_ISUID | S_ISGID);
650 	}
651 	TMPFS_NODE_UNLOCK(node);
652 done:
653 
654 	tmpfs_knote(vp, kflags);
655 
656 
657 	lwkt_reltoken(&vp->v_mount->mnt_token);
658 	return(error);
659 }
660 
661 static int
662 tmpfs_advlock (struct vop_advlock_args *ap)
663 {
664 	struct tmpfs_node *node;
665 	struct vnode *vp = ap->a_vp;
666 
667 	node = VP_TO_TMPFS_NODE(vp);
668 
669 	return (lf_advlock(ap, &node->tn_advlock, node->tn_size));
670 }
671 
672 /*
673  * The strategy function is typically only called when memory pressure
674  * forces the system to attempt to pageout pages.  It can also be called
675  * by [n]vtruncbuf() when a truncation cuts a page in half.  Normal write
676  * operations
677  */
678 static int
679 tmpfs_strategy(struct vop_strategy_args *ap)
680 {
681 	struct bio *bio = ap->a_bio;
682 	struct bio *nbio;
683 	struct buf *bp = bio->bio_buf;
684 	struct vnode *vp = ap->a_vp;
685 	struct tmpfs_node *node;
686 	vm_object_t uobj;
687 	vm_page_t m;
688 	int i;
689 
690 	if (vp->v_type != VREG) {
691 		bp->b_resid = bp->b_bcount;
692 		bp->b_flags |= B_ERROR | B_INVAL;
693 		bp->b_error = EINVAL;
694 		biodone(bio);
695 		return(0);
696 	}
697 
698 	lwkt_gettoken(&vp->v_mount->mnt_token);
699 	node = VP_TO_TMPFS_NODE(vp);
700 
701 	uobj = node->tn_reg.tn_aobj;
702 
703 	/*
704 	 * Don't bother flushing to swap if there is no swap, just
705 	 * ensure that the pages are marked as needing a commit (still).
706 	 */
707 	if (bp->b_cmd == BUF_CMD_WRITE && vm_swap_size == 0) {
708 		for (i = 0; i < bp->b_xio.xio_npages; ++i) {
709 			m = bp->b_xio.xio_pages[i];
710 			vm_page_need_commit(m);
711 		}
712 		bp->b_resid = 0;
713 		bp->b_error = 0;
714 		biodone(bio);
715 	} else {
716 		nbio = push_bio(bio);
717 		nbio->bio_done = tmpfs_strategy_done;
718 		nbio->bio_offset = bio->bio_offset;
719 		swap_pager_strategy(uobj, nbio);
720 	}
721 
722 	lwkt_reltoken(&vp->v_mount->mnt_token);
723 	return 0;
724 }
725 
726 /*
727  * If we were unable to commit the pages to swap make sure they are marked
728  * as needing a commit (again).  If we were, clear the flag to allow the
729  * pages to be freed.
730  */
731 static void
732 tmpfs_strategy_done(struct bio *bio)
733 {
734 	struct buf *bp;
735 	vm_page_t m;
736 	int i;
737 
738 	bp = bio->bio_buf;
739 
740 	if (bp->b_flags & B_ERROR) {
741 		bp->b_flags &= ~B_ERROR;
742 		bp->b_error = 0;
743 		bp->b_resid = 0;
744 		for (i = 0; i < bp->b_xio.xio_npages; ++i) {
745 			m = bp->b_xio.xio_pages[i];
746 			vm_page_need_commit(m);
747 		}
748 	} else {
749 		for (i = 0; i < bp->b_xio.xio_npages; ++i) {
750 			m = bp->b_xio.xio_pages[i];
751 			vm_page_clear_commit(m);
752 		}
753 	}
754 	bio = pop_bio(bio);
755 	biodone(bio);
756 }
757 
758 static int
759 tmpfs_bmap(struct vop_bmap_args *ap)
760 {
761 	if (ap->a_doffsetp != NULL)
762 		*ap->a_doffsetp = ap->a_loffset;
763 	if (ap->a_runp != NULL)
764 		*ap->a_runp = 0;
765 	if (ap->a_runb != NULL)
766 		*ap->a_runb = 0;
767 
768 	return 0;
769 }
770 
771 /* --------------------------------------------------------------------- */
772 
773 static int
774 tmpfs_nremove(struct vop_nremove_args *v)
775 {
776 	struct vnode *dvp = v->a_dvp;
777 	struct namecache *ncp = v->a_nch->ncp;
778 	struct vnode *vp;
779 	int error;
780 	struct tmpfs_dirent *de;
781 	struct tmpfs_mount *tmp;
782 	struct tmpfs_node *dnode;
783 	struct tmpfs_node *node;
784 
785 	/*
786 	 * We have to acquire the vp from v->a_nch because we will likely
787 	 * unresolve the namecache entry, and a vrele/vput is needed to
788 	 * trigger the tmpfs_inactive/tmpfs_reclaim sequence.
789 	 *
790 	 * We have to use vget to clear any inactive state on the vnode,
791 	 * otherwise the vnode may remain inactive and thus tmpfs_inactive
792 	 * will not get called when we release it.
793 	 */
794 	error = cache_vget(v->a_nch, v->a_cred, LK_SHARED, &vp);
795 	KKASSERT(error == 0);
796 	vn_unlock(vp);
797 
798 	if (vp->v_type == VDIR) {
799 		error = EISDIR;
800 		goto out;
801 	}
802 
803 	dnode = VP_TO_TMPFS_DIR(dvp);
804 	node = VP_TO_TMPFS_NODE(vp);
805 	tmp = VFS_TO_TMPFS(vp->v_mount);
806 	de = tmpfs_dir_lookup(dnode, node, ncp);
807 	if (de == NULL) {
808 		error = ENOENT;
809 		goto out;
810 	}
811 
812 	/* Files marked as immutable or append-only cannot be deleted. */
813 	if ((node->tn_flags & (IMMUTABLE | APPEND | NOUNLINK)) ||
814 	    (dnode->tn_flags & APPEND)) {
815 		error = EPERM;
816 		goto out;
817 	}
818 
819 	/* Remove the entry from the directory; as it is a file, we do not
820 	 * have to change the number of hard links of the directory. */
821 	tmpfs_dir_detach(dnode, de);
822 
823 	/* Free the directory entry we just deleted.  Note that the node
824 	 * referred by it will not be removed until the vnode is really
825 	 * reclaimed. */
826 	tmpfs_free_dirent(tmp, de);
827 
828 	if (node->tn_links > 0) {
829 	        TMPFS_NODE_LOCK(node);
830 		node->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \
831 	                TMPFS_NODE_MODIFIED;
832 	        TMPFS_NODE_UNLOCK(node);
833 	}
834 
835 	cache_unlink(v->a_nch);
836 	tmpfs_knote(vp, NOTE_DELETE);
837 	tmpfs_knote(dvp, NOTE_WRITE);
838 	error = 0;
839 
840 out:
841 	vrele(vp);
842 
843 	return error;
844 }
845 
846 /* --------------------------------------------------------------------- */
847 
848 static int
849 tmpfs_nlink(struct vop_nlink_args *v)
850 {
851 	struct vnode *dvp = v->a_dvp;
852 	struct vnode *vp = v->a_vp;
853 	struct namecache *ncp = v->a_nch->ncp;
854 	struct tmpfs_dirent *de;
855 	struct tmpfs_node *node;
856 	struct tmpfs_node *dnode;
857 	int error;
858 
859 	KKASSERT(dvp != vp); /* XXX When can this be false? */
860 
861 	node = VP_TO_TMPFS_NODE(vp);
862 	dnode = VP_TO_TMPFS_NODE(dvp);
863 
864 	/* XXX: Why aren't the following two tests done by the caller? */
865 
866 	/* Hard links of directories are forbidden. */
867 	if (vp->v_type == VDIR) {
868 		error = EPERM;
869 		goto out;
870 	}
871 
872 	/* Cannot create cross-device links. */
873 	if (dvp->v_mount != vp->v_mount) {
874 		error = EXDEV;
875 		goto out;
876 	}
877 
878 	/* Ensure that we do not overflow the maximum number of links imposed
879 	 * by the system. */
880 	KKASSERT(node->tn_links <= LINK_MAX);
881 	if (node->tn_links == LINK_MAX) {
882 		error = EMLINK;
883 		goto out;
884 	}
885 
886 	/* We cannot create links of files marked immutable or append-only. */
887 	if (node->tn_flags & (IMMUTABLE | APPEND)) {
888 		error = EPERM;
889 		goto out;
890 	}
891 
892 	/* Allocate a new directory entry to represent the node. */
893 	error = tmpfs_alloc_dirent(VFS_TO_TMPFS(vp->v_mount), node,
894 	    ncp->nc_name, ncp->nc_nlen, &de);
895 	if (error != 0)
896 		goto out;
897 
898 	/* Insert the new directory entry into the appropriate directory. */
899 	tmpfs_dir_attach(dnode, de);
900 
901 	/* vp link count has changed, so update node times. */
902 
903 	TMPFS_NODE_LOCK(node);
904 	node->tn_status |= TMPFS_NODE_CHANGED;
905 	TMPFS_NODE_UNLOCK(node);
906 	tmpfs_update(vp);
907 
908 	tmpfs_knote(vp, NOTE_LINK);
909 	cache_setunresolved(v->a_nch);
910 	cache_setvp(v->a_nch, vp);
911 	tmpfs_knote(dvp, NOTE_WRITE);
912 	error = 0;
913 
914 out:
915 	return error;
916 }
917 
918 /* --------------------------------------------------------------------- */
919 
920 static int
921 tmpfs_nrename(struct vop_nrename_args *v)
922 {
923 	struct vnode *fdvp = v->a_fdvp;
924 	struct namecache *fncp = v->a_fnch->ncp;
925 	struct vnode *fvp = fncp->nc_vp;
926 	struct vnode *tdvp = v->a_tdvp;
927 	struct namecache *tncp = v->a_tnch->ncp;
928 	struct vnode *tvp;
929 	struct tmpfs_dirent *de, *tde;
930 	struct tmpfs_mount *tmp;
931 	struct tmpfs_node *fdnode;
932 	struct tmpfs_node *fnode;
933 	struct tmpfs_node *tnode;
934 	struct tmpfs_node *tdnode;
935 	char *newname;
936 	char *oldname;
937 	int error;
938 
939 	/*
940 	 * Because tvp can get overwritten we have to vget it instead of
941 	 * just vref or use it, otherwise it's VINACTIVE flag may not get
942 	 * cleared and the node won't get destroyed.
943 	 */
944 	error = cache_vget(v->a_tnch, v->a_cred, LK_SHARED, &tvp);
945 	if (error == 0) {
946 		tnode = VP_TO_TMPFS_NODE(tvp);
947 		vn_unlock(tvp);
948 	} else {
949 		tnode = NULL;
950 	}
951 
952 	/* Disallow cross-device renames.
953 	 * XXX Why isn't this done by the caller? */
954 	if (fvp->v_mount != tdvp->v_mount ||
955 	    (tvp != NULL && fvp->v_mount != tvp->v_mount)) {
956 		error = EXDEV;
957 		goto out;
958 	}
959 
960 	tmp = VFS_TO_TMPFS(tdvp->v_mount);
961 	tdnode = VP_TO_TMPFS_DIR(tdvp);
962 
963 	/* If source and target are the same file, there is nothing to do. */
964 	if (fvp == tvp) {
965 		error = 0;
966 		goto out;
967 	}
968 
969 	fdnode = VP_TO_TMPFS_DIR(fdvp);
970 	fnode = VP_TO_TMPFS_NODE(fvp);
971 	de = tmpfs_dir_lookup(fdnode, fnode, fncp);
972 
973 	/* Avoid manipulating '.' and '..' entries. */
974 	if (de == NULL) {
975 		error = ENOENT;
976 		goto out_locked;
977 	}
978 	KKASSERT(de->td_node == fnode);
979 
980 	/*
981 	 * If replacing an entry in the target directory and that entry
982 	 * is a directory, it must be empty.
983 	 *
984 	 * Kern_rename gurantees the destination to be a directory
985 	 * if the source is one (it does?).
986 	 */
987 	if (tvp != NULL) {
988 		KKASSERT(tnode != NULL);
989 
990 		if ((tnode->tn_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
991 		    (tdnode->tn_flags & (APPEND | IMMUTABLE))) {
992 			error = EPERM;
993 			goto out_locked;
994 		}
995 
996 		if (fnode->tn_type == VDIR && tnode->tn_type == VDIR) {
997 			if (tnode->tn_size > 0) {
998 				error = ENOTEMPTY;
999 				goto out_locked;
1000 			}
1001 		} else if (fnode->tn_type == VDIR && tnode->tn_type != VDIR) {
1002 			error = ENOTDIR;
1003 			goto out_locked;
1004 		} else if (fnode->tn_type != VDIR && tnode->tn_type == VDIR) {
1005 			error = EISDIR;
1006 			goto out_locked;
1007 		} else {
1008 			KKASSERT(fnode->tn_type != VDIR &&
1009 				tnode->tn_type != VDIR);
1010 		}
1011 	}
1012 
1013 	if ((fnode->tn_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
1014 	    (fdnode->tn_flags & (APPEND | IMMUTABLE))) {
1015 		error = EPERM;
1016 		goto out_locked;
1017 	}
1018 
1019 	/*
1020 	 * Ensure that we have enough memory to hold the new name, if it
1021 	 * has to be changed.
1022 	 */
1023 	if (fncp->nc_nlen != tncp->nc_nlen ||
1024 	    bcmp(fncp->nc_name, tncp->nc_name, fncp->nc_nlen) != 0) {
1025 		newname = kmalloc(tncp->nc_nlen + 1, tmp->tm_name_zone,
1026 				  M_WAITOK | M_NULLOK);
1027 		if (newname == NULL) {
1028 			error = ENOSPC;
1029 			goto out_locked;
1030 		}
1031 		bcopy(tncp->nc_name, newname, tncp->nc_nlen);
1032 		newname[tncp->nc_nlen] = '\0';
1033 	} else {
1034 		newname = NULL;
1035 	}
1036 
1037 	/*
1038 	 * Unlink entry from source directory.  Note that the kernel has
1039 	 * already checked for illegal recursion cases (renaming a directory
1040 	 * into a subdirectory of itself).
1041 	 */
1042 	if (fdnode != tdnode) {
1043 		tmpfs_dir_detach(fdnode, de);
1044 	} else {
1045 		RB_REMOVE(tmpfs_dirtree, &fdnode->tn_dir.tn_dirtree, de);
1046 	}
1047 
1048 	/*
1049 	 * Handle any name change.  Swap with newname, we will
1050 	 * deallocate it at the end.
1051 	 */
1052 	if (newname != NULL) {
1053 #if 0
1054 		TMPFS_NODE_LOCK(fnode);
1055 		fnode->tn_status |= TMPFS_NODE_CHANGED;
1056 		TMPFS_NODE_UNLOCK(fnode);
1057 #endif
1058 		oldname = de->td_name;
1059 		de->td_name = newname;
1060 		de->td_namelen = (uint16_t)tncp->nc_nlen;
1061 		newname = oldname;
1062 	}
1063 
1064 	/*
1065 	 * If we are overwriting an entry, we have to remove the old one
1066 	 * from the target directory.
1067 	 */
1068 	if (tvp != NULL) {
1069 		/* Remove the old entry from the target directory. */
1070 		tde = tmpfs_dir_lookup(tdnode, tnode, tncp);
1071 		tmpfs_dir_detach(tdnode, tde);
1072 		tmpfs_knote(tdnode->tn_vnode, NOTE_DELETE);
1073 
1074 		/*
1075 		 * Free the directory entry we just deleted.  Note that the
1076 		 * node referred by it will not be removed until the vnode is
1077 		 * really reclaimed.
1078 		 */
1079 		tmpfs_free_dirent(VFS_TO_TMPFS(tvp->v_mount), tde);
1080 		/*cache_inval_vp(tvp, CINV_DESTROY);*/
1081 	}
1082 
1083 	/*
1084 	 * Link entry to target directory.  If the entry
1085 	 * represents a directory move the parent linkage
1086 	 * as well.
1087 	 */
1088 	if (fdnode != tdnode) {
1089 		if (de->td_node->tn_type == VDIR) {
1090 			TMPFS_VALIDATE_DIR(fnode);
1091 		}
1092 		tmpfs_dir_attach(tdnode, de);
1093 	} else {
1094 		TMPFS_NODE_LOCK(tdnode);
1095 		tdnode->tn_status |= TMPFS_NODE_MODIFIED;
1096 		RB_INSERT(tmpfs_dirtree, &tdnode->tn_dir.tn_dirtree, de);
1097 		TMPFS_NODE_UNLOCK(tdnode);
1098 	}
1099 
1100 	/*
1101 	 * Finish up
1102 	 */
1103 	if (newname) {
1104 		kfree(newname, tmp->tm_name_zone);
1105 		newname = NULL;
1106 	}
1107 	cache_rename(v->a_fnch, v->a_tnch);
1108 	tmpfs_knote(v->a_fdvp, NOTE_WRITE);
1109 	tmpfs_knote(v->a_tdvp, NOTE_WRITE);
1110 	if (fnode->tn_vnode)
1111 		tmpfs_knote(fnode->tn_vnode, NOTE_RENAME);
1112 	error = 0;
1113 
1114 out_locked:
1115 	;
1116 
1117 out:
1118 	if (tvp)
1119 		vrele(tvp);
1120 
1121 	return error;
1122 }
1123 
1124 /* --------------------------------------------------------------------- */
1125 
1126 static int
1127 tmpfs_nmkdir(struct vop_nmkdir_args *v)
1128 {
1129 	struct vnode *dvp = v->a_dvp;
1130 	struct vnode **vpp = v->a_vpp;
1131 	struct namecache *ncp = v->a_nch->ncp;
1132 	struct vattr *vap = v->a_vap;
1133 	struct ucred *cred = v->a_cred;
1134 	int error;
1135 
1136 	KKASSERT(vap->va_type == VDIR);
1137 
1138 	error = tmpfs_alloc_file(dvp, vpp, vap, ncp, cred, NULL);
1139 	if (error == 0) {
1140 		cache_setunresolved(v->a_nch);
1141 		cache_setvp(v->a_nch, *vpp);
1142 		tmpfs_knote(dvp, NOTE_WRITE | NOTE_LINK);
1143 	}
1144 
1145 	return error;
1146 }
1147 
1148 /* --------------------------------------------------------------------- */
1149 
1150 static int
1151 tmpfs_nrmdir(struct vop_nrmdir_args *v)
1152 {
1153 	struct vnode *dvp = v->a_dvp;
1154 	struct namecache *ncp = v->a_nch->ncp;
1155 	struct vnode *vp;
1156 	struct tmpfs_dirent *de;
1157 	struct tmpfs_mount *tmp;
1158 	struct tmpfs_node *dnode;
1159 	struct tmpfs_node *node;
1160 	int error;
1161 
1162 	/*
1163 	 * We have to acquire the vp from v->a_nch because we will likely
1164 	 * unresolve the namecache entry, and a vrele/vput is needed to
1165 	 * trigger the tmpfs_inactive/tmpfs_reclaim sequence.
1166 	 *
1167 	 * We have to use vget to clear any inactive state on the vnode,
1168 	 * otherwise the vnode may remain inactive and thus tmpfs_inactive
1169 	 * will not get called when we release it.
1170 	 */
1171 	error = cache_vget(v->a_nch, v->a_cred, LK_SHARED, &vp);
1172 	KKASSERT(error == 0);
1173 	vn_unlock(vp);
1174 
1175 	/*
1176 	 * Prevalidate so we don't hit an assertion later
1177 	 */
1178 	if (vp->v_type != VDIR) {
1179 		error = ENOTDIR;
1180 		goto out;
1181 	}
1182 
1183 	tmp = VFS_TO_TMPFS(dvp->v_mount);
1184 	dnode = VP_TO_TMPFS_DIR(dvp);
1185 	node = VP_TO_TMPFS_DIR(vp);
1186 
1187 	/* Directories with more than two entries ('.' and '..') cannot be
1188 	 * removed. */
1189 	 if (node->tn_size > 0) {
1190 		 error = ENOTEMPTY;
1191 		 goto out;
1192 	 }
1193 
1194 	if ((dnode->tn_flags & APPEND)
1195 	    || (node->tn_flags & (NOUNLINK | IMMUTABLE | APPEND))) {
1196 		error = EPERM;
1197 		goto out;
1198 	}
1199 
1200 	/* This invariant holds only if we are not trying to remove "..".
1201 	  * We checked for that above so this is safe now. */
1202 	KKASSERT(node->tn_dir.tn_parent == dnode);
1203 
1204 	/* Get the directory entry associated with node (vp).  This was
1205 	 * filled by tmpfs_lookup while looking up the entry. */
1206 	de = tmpfs_dir_lookup(dnode, node, ncp);
1207 	KKASSERT(TMPFS_DIRENT_MATCHES(de,
1208 	    ncp->nc_name,
1209 	    ncp->nc_nlen));
1210 
1211 	/* Check flags to see if we are allowed to remove the directory. */
1212 	if ((dnode->tn_flags & APPEND) ||
1213 	    node->tn_flags & (NOUNLINK | IMMUTABLE | APPEND)) {
1214 		error = EPERM;
1215 		goto out;
1216 	}
1217 
1218 
1219 	/* Detach the directory entry from the directory (dnode). */
1220 	tmpfs_dir_detach(dnode, de);
1221 
1222 	/* No vnode should be allocated for this entry from this point */
1223 	TMPFS_NODE_LOCK(node);
1224 	TMPFS_ASSERT_ELOCKED(node);
1225 	TMPFS_NODE_LOCK(dnode);
1226 	TMPFS_ASSERT_ELOCKED(dnode);
1227 
1228 	/*
1229 	 * Must set parent linkage to NULL (tested by ncreate to disallow
1230 	 * the creation of new files/dirs in a deleted directory)
1231 	 */
1232 	node->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \
1233 	    TMPFS_NODE_MODIFIED;
1234 
1235 	dnode->tn_status |= TMPFS_NODE_ACCESSED | \
1236 	    TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED;
1237 
1238 	TMPFS_NODE_UNLOCK(dnode);
1239 	TMPFS_NODE_UNLOCK(node);
1240 
1241 	/* Free the directory entry we just deleted.  Note that the node
1242 	 * referred by it will not be removed until the vnode is really
1243 	 * reclaimed. */
1244 	tmpfs_free_dirent(tmp, de);
1245 
1246 	/* Release the deleted vnode (will destroy the node, notify
1247 	 * interested parties and clean it from the cache). */
1248 
1249 	TMPFS_NODE_LOCK(dnode);
1250 	dnode->tn_status |= TMPFS_NODE_CHANGED;
1251 	TMPFS_NODE_UNLOCK(dnode);
1252 	tmpfs_update(dvp);
1253 
1254 	cache_unlink(v->a_nch);
1255 	tmpfs_knote(dvp, NOTE_WRITE | NOTE_LINK);
1256 	error = 0;
1257 
1258 out:
1259 	vrele(vp);
1260 
1261 	return error;
1262 }
1263 
1264 /* --------------------------------------------------------------------- */
1265 
1266 static int
1267 tmpfs_nsymlink(struct vop_nsymlink_args *v)
1268 {
1269 	struct vnode *dvp = v->a_dvp;
1270 	struct vnode **vpp = v->a_vpp;
1271 	struct namecache *ncp = v->a_nch->ncp;
1272 	struct vattr *vap = v->a_vap;
1273 	struct ucred *cred = v->a_cred;
1274 	char *target = v->a_target;
1275 	int error;
1276 
1277 	vap->va_type = VLNK;
1278 	error = tmpfs_alloc_file(dvp, vpp, vap, ncp, cred, target);
1279 	if (error == 0) {
1280 		tmpfs_knote(*vpp, NOTE_WRITE);
1281 		cache_setunresolved(v->a_nch);
1282 		cache_setvp(v->a_nch, *vpp);
1283 	}
1284 
1285 	return error;
1286 }
1287 
1288 /* --------------------------------------------------------------------- */
1289 
1290 static int
1291 tmpfs_readdir(struct vop_readdir_args *v)
1292 {
1293 	struct vnode *vp = v->a_vp;
1294 	struct uio *uio = v->a_uio;
1295 	int *eofflag = v->a_eofflag;
1296 	off_t **cookies = v->a_cookies;
1297 	int *ncookies = v->a_ncookies;
1298 	struct tmpfs_mount *tmp;
1299 	int error;
1300 	off_t startoff;
1301 	off_t cnt = 0;
1302 	struct tmpfs_node *node;
1303 
1304 	/* This operation only makes sense on directory nodes. */
1305 	if (vp->v_type != VDIR)
1306 		return ENOTDIR;
1307 
1308 	tmp = VFS_TO_TMPFS(vp->v_mount);
1309 	node = VP_TO_TMPFS_DIR(vp);
1310 	startoff = uio->uio_offset;
1311 
1312 	if (uio->uio_offset == TMPFS_DIRCOOKIE_DOT) {
1313 		error = tmpfs_dir_getdotdent(node, uio);
1314 		if (error != 0)
1315 			goto outok;
1316 		cnt++;
1317 	}
1318 
1319 	if (uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT) {
1320 		error = tmpfs_dir_getdotdotdent(tmp, node, uio);
1321 		if (error != 0)
1322 			goto outok;
1323 		cnt++;
1324 	}
1325 
1326 	error = tmpfs_dir_getdents(node, uio, &cnt);
1327 
1328 outok:
1329 	KKASSERT(error >= -1);
1330 
1331 	if (error == -1)
1332 		error = 0;
1333 
1334 	if (eofflag != NULL)
1335 		*eofflag =
1336 		    (error == 0 && uio->uio_offset == TMPFS_DIRCOOKIE_EOF);
1337 
1338 	/* Update NFS-related variables. */
1339 	if (error == 0 && cookies != NULL && ncookies != NULL) {
1340 		off_t i;
1341 		off_t off = startoff;
1342 		struct tmpfs_dirent *de = NULL;
1343 
1344 		*ncookies = cnt;
1345 		*cookies = kmalloc(cnt * sizeof(off_t), M_TEMP, M_WAITOK);
1346 
1347 		for (i = 0; i < cnt; i++) {
1348 			KKASSERT(off != TMPFS_DIRCOOKIE_EOF);
1349 			if (off == TMPFS_DIRCOOKIE_DOT) {
1350 				off = TMPFS_DIRCOOKIE_DOTDOT;
1351 			} else {
1352 				if (off == TMPFS_DIRCOOKIE_DOTDOT) {
1353 					de = RB_MIN(tmpfs_dirtree, &node->tn_dir.tn_dirtree);
1354 				} else if (de != NULL) {
1355 					de = RB_NEXT(tmpfs_dirtree, &node->tn_dir.tn_dirtree, de);
1356 				} else {
1357 					de = tmpfs_dir_lookupbycookie(node,
1358 					    off);
1359 					KKASSERT(de != NULL);
1360 					de = RB_NEXT(tmpfs_dirtree, &node->tn_dir.tn_dirtree, de);
1361 				}
1362 				if (de == NULL)
1363 					off = TMPFS_DIRCOOKIE_EOF;
1364 				else
1365 					off = tmpfs_dircookie(de);
1366 			}
1367 
1368 			(*cookies)[i] = off;
1369 		}
1370 		KKASSERT(uio->uio_offset == off);
1371 	}
1372 
1373 	return error;
1374 }
1375 
1376 /* --------------------------------------------------------------------- */
1377 
1378 static int
1379 tmpfs_readlink(struct vop_readlink_args *v)
1380 {
1381 	struct vnode *vp = v->a_vp;
1382 	struct uio *uio = v->a_uio;
1383 
1384 	int error;
1385 	struct tmpfs_node *node;
1386 
1387 	KKASSERT(uio->uio_offset == 0);
1388 	KKASSERT(vp->v_type == VLNK);
1389 
1390 	node = VP_TO_TMPFS_NODE(vp);
1391 
1392 	error = uiomove(node->tn_link, MIN(node->tn_size, uio->uio_resid),
1393 	    uio);
1394 	TMPFS_NODE_LOCK(node);
1395 	node->tn_status |= TMPFS_NODE_ACCESSED;
1396 	TMPFS_NODE_UNLOCK(node);
1397 
1398 	return error;
1399 }
1400 
1401 /* --------------------------------------------------------------------- */
1402 
1403 static int
1404 tmpfs_inactive(struct vop_inactive_args *v)
1405 {
1406 	struct vnode *vp = v->a_vp;
1407 	struct tmpfs_node *node;
1408 
1409 	node = VP_TO_TMPFS_NODE(vp);
1410 
1411 	/*
1412 	 * Degenerate case
1413 	 */
1414 	if (node == NULL) {
1415 		vrecycle(vp);
1416 		return(0);
1417 	}
1418 
1419 	/*
1420 	 * Get rid of unreferenced deleted vnodes sooner rather than
1421 	 * later so the data memory can be recovered immediately.
1422 	 *
1423 	 * We must truncate the vnode to prevent the normal reclamation
1424 	 * path from flushing the data for the removed file to disk.
1425 	 */
1426 	TMPFS_NODE_LOCK(node);
1427 	if ((node->tn_vpstate & TMPFS_VNODE_ALLOCATING) == 0 &&
1428 	    node->tn_links == 0)
1429 	{
1430 		node->tn_vpstate = TMPFS_VNODE_DOOMED;
1431 		TMPFS_NODE_UNLOCK(node);
1432 		if (node->tn_type == VREG)
1433 			tmpfs_truncate(vp, 0);
1434 		vrecycle(vp);
1435 	} else {
1436 		TMPFS_NODE_UNLOCK(node);
1437 	}
1438 
1439 	return 0;
1440 }
1441 
1442 /* --------------------------------------------------------------------- */
1443 
1444 int
1445 tmpfs_reclaim(struct vop_reclaim_args *v)
1446 {
1447 	struct vnode *vp = v->a_vp;
1448 	struct tmpfs_mount *tmp;
1449 	struct tmpfs_node *node;
1450 
1451 	node = VP_TO_TMPFS_NODE(vp);
1452 	tmp = VFS_TO_TMPFS(vp->v_mount);
1453 
1454 	tmpfs_free_vp(vp);
1455 
1456 	/*
1457 	 * If the node referenced by this vnode was deleted by the
1458 	 * user, we must free its associated data structures now that
1459 	 * the vnode is being reclaimed.
1460 	 *
1461 	 * Directories have an extra link ref.
1462 	 */
1463 	TMPFS_NODE_LOCK(node);
1464 	if ((node->tn_vpstate & TMPFS_VNODE_ALLOCATING) == 0 &&
1465 	    node->tn_links == 0) {
1466 		node->tn_vpstate = TMPFS_VNODE_DOOMED;
1467 		tmpfs_free_node(tmp, node);
1468 		/* eats the lock */
1469 	} else {
1470 		TMPFS_NODE_UNLOCK(node);
1471 	}
1472 
1473 	KKASSERT(vp->v_data == NULL);
1474 	return 0;
1475 }
1476 
1477 /* --------------------------------------------------------------------- */
1478 
1479 static int
1480 tmpfs_mountctl(struct vop_mountctl_args *ap)
1481 {
1482 	struct tmpfs_mount *tmp;
1483 	struct mount *mp;
1484 	int rc;
1485 
1486 	switch (ap->a_op) {
1487 	case (MOUNTCTL_SET_EXPORT):
1488 		mp = ap->a_head.a_ops->head.vv_mount;
1489 		tmp = (struct tmpfs_mount *) mp->mnt_data;
1490 
1491 		if (ap->a_ctllen != sizeof(struct export_args))
1492 			rc = (EINVAL);
1493 		else
1494 			rc = vfs_export(mp, &tmp->tm_export,
1495 					(const struct export_args *) ap->a_ctl);
1496 		break;
1497 	default:
1498 		rc = vop_stdmountctl(ap);
1499 		break;
1500 	}
1501 	return (rc);
1502 }
1503 
1504 /* --------------------------------------------------------------------- */
1505 
1506 static int
1507 tmpfs_print(struct vop_print_args *v)
1508 {
1509 	struct vnode *vp = v->a_vp;
1510 
1511 	struct tmpfs_node *node;
1512 
1513 	node = VP_TO_TMPFS_NODE(vp);
1514 
1515 	kprintf("tag VT_TMPFS, tmpfs_node %p, flags 0x%x, links %d\n",
1516 	    node, node->tn_flags, node->tn_links);
1517 	kprintf("\tmode 0%o, owner %d, group %d, size %ju, status 0x%x\n",
1518 	    node->tn_mode, node->tn_uid, node->tn_gid,
1519 	    (uintmax_t)node->tn_size, node->tn_status);
1520 
1521 	if (vp->v_type == VFIFO)
1522 		fifo_printinfo(vp);
1523 
1524 	kprintf("\n");
1525 
1526 	return 0;
1527 }
1528 
1529 /* --------------------------------------------------------------------- */
1530 
1531 static int
1532 tmpfs_pathconf(struct vop_pathconf_args *v)
1533 {
1534 	int name = v->a_name;
1535 	register_t *retval = v->a_retval;
1536 
1537 	int error;
1538 
1539 	error = 0;
1540 
1541 	switch (name) {
1542 	case _PC_LINK_MAX:
1543 		*retval = LINK_MAX;
1544 		break;
1545 
1546 	case _PC_NAME_MAX:
1547 		*retval = NAME_MAX;
1548 		break;
1549 
1550 	case _PC_PATH_MAX:
1551 		*retval = PATH_MAX;
1552 		break;
1553 
1554 	case _PC_PIPE_BUF:
1555 		*retval = PIPE_BUF;
1556 		break;
1557 
1558 	case _PC_CHOWN_RESTRICTED:
1559 		*retval = 1;
1560 		break;
1561 
1562 	case _PC_NO_TRUNC:
1563 		*retval = 1;
1564 		break;
1565 
1566 	case _PC_SYNC_IO:
1567 		*retval = 1;
1568 		break;
1569 
1570 	case _PC_FILESIZEBITS:
1571 		*retval = 0; /* XXX Don't know which value should I return. */
1572 		break;
1573 
1574 	default:
1575 		error = EINVAL;
1576 	}
1577 
1578 	return error;
1579 }
1580 
1581 /************************************************************************
1582  *                          KQFILTER OPS                                *
1583  ************************************************************************/
1584 
1585 static void filt_tmpfsdetach(struct knote *kn);
1586 static int filt_tmpfsread(struct knote *kn, long hint);
1587 static int filt_tmpfswrite(struct knote *kn, long hint);
1588 static int filt_tmpfsvnode(struct knote *kn, long hint);
1589 
1590 static struct filterops tmpfsread_filtops =
1591 	{ FILTEROP_ISFD, NULL, filt_tmpfsdetach, filt_tmpfsread };
1592 static struct filterops tmpfswrite_filtops =
1593 	{ FILTEROP_ISFD, NULL, filt_tmpfsdetach, filt_tmpfswrite };
1594 static struct filterops tmpfsvnode_filtops =
1595 	{ FILTEROP_ISFD, NULL, filt_tmpfsdetach, filt_tmpfsvnode };
1596 
1597 static int
1598 tmpfs_kqfilter (struct vop_kqfilter_args *ap)
1599 {
1600 	struct vnode *vp = ap->a_vp;
1601 	struct knote *kn = ap->a_kn;
1602 
1603 	switch (kn->kn_filter) {
1604 	case EVFILT_READ:
1605 		kn->kn_fop = &tmpfsread_filtops;
1606 		break;
1607 	case EVFILT_WRITE:
1608 		kn->kn_fop = &tmpfswrite_filtops;
1609 		break;
1610 	case EVFILT_VNODE:
1611 		kn->kn_fop = &tmpfsvnode_filtops;
1612 		break;
1613 	default:
1614 		return (EOPNOTSUPP);
1615 	}
1616 
1617 	kn->kn_hook = (caddr_t)vp;
1618 
1619 	knote_insert(&vp->v_pollinfo.vpi_kqinfo.ki_note, kn);
1620 
1621 	return(0);
1622 }
1623 
1624 static void
1625 filt_tmpfsdetach(struct knote *kn)
1626 {
1627 	struct vnode *vp = (void *)kn->kn_hook;
1628 
1629 	knote_remove(&vp->v_pollinfo.vpi_kqinfo.ki_note, kn);
1630 }
1631 
1632 static int
1633 filt_tmpfsread(struct knote *kn, long hint)
1634 {
1635 	struct vnode *vp = (void *)kn->kn_hook;
1636 	struct tmpfs_node *node = VP_TO_TMPFS_NODE(vp);
1637 	off_t off;
1638 
1639 	if (hint == NOTE_REVOKE) {
1640 		kn->kn_flags |= (EV_EOF | EV_NODATA | EV_ONESHOT);
1641 		return(1);
1642 	}
1643 
1644 	/*
1645 	 * Interlock against MP races when performing this function.
1646 	 */
1647 	lwkt_gettoken(&vp->v_mount->mnt_token);
1648 	off = node->tn_size - kn->kn_fp->f_offset;
1649 	kn->kn_data = (off < INTPTR_MAX) ? off : INTPTR_MAX;
1650 	if (kn->kn_sfflags & NOTE_OLDAPI) {
1651 		lwkt_reltoken(&vp->v_mount->mnt_token);
1652 		return(1);
1653 	}
1654 
1655 	if (kn->kn_data == 0) {
1656 		kn->kn_data = (off < INTPTR_MAX) ? off : INTPTR_MAX;
1657 	}
1658 	lwkt_reltoken(&vp->v_mount->mnt_token);
1659 	return (kn->kn_data != 0);
1660 }
1661 
1662 static int
1663 filt_tmpfswrite(struct knote *kn, long hint)
1664 {
1665 	if (hint == NOTE_REVOKE)
1666 		kn->kn_flags |= (EV_EOF | EV_NODATA | EV_ONESHOT);
1667 	kn->kn_data = 0;
1668 	return (1);
1669 }
1670 
1671 static int
1672 filt_tmpfsvnode(struct knote *kn, long hint)
1673 {
1674 	if (kn->kn_sfflags & hint)
1675 		kn->kn_fflags |= hint;
1676 	if (hint == NOTE_REVOKE) {
1677 		kn->kn_flags |= (EV_EOF | EV_NODATA);
1678 		return (1);
1679 	}
1680 	return (kn->kn_fflags != 0);
1681 }
1682 
1683 
1684 /* --------------------------------------------------------------------- */
1685 
1686 /*
1687  * vnode operations vector used for files stored in a tmpfs file system.
1688  */
1689 struct vop_ops tmpfs_vnode_vops = {
1690 	.vop_default =			vop_defaultop,
1691 	.vop_getpages = 		vop_stdgetpages,
1692 	.vop_putpages = 		vop_stdputpages,
1693 	.vop_ncreate =			tmpfs_ncreate,
1694 	.vop_nresolve =			tmpfs_nresolve,
1695 	.vop_nlookupdotdot =		tmpfs_nlookupdotdot,
1696 	.vop_nmknod =			tmpfs_nmknod,
1697 	.vop_open =			tmpfs_open,
1698 	.vop_close =			tmpfs_close,
1699 	.vop_access =			tmpfs_access,
1700 	.vop_getattr =			tmpfs_getattr,
1701 	.vop_setattr =			tmpfs_setattr,
1702 	.vop_read =			tmpfs_read,
1703 	.vop_write =			tmpfs_write,
1704 	.vop_fsync =			tmpfs_fsync,
1705 	.vop_mountctl =			tmpfs_mountctl,
1706 	.vop_nremove =			tmpfs_nremove,
1707 	.vop_nlink =			tmpfs_nlink,
1708 	.vop_nrename =			tmpfs_nrename,
1709 	.vop_nmkdir =			tmpfs_nmkdir,
1710 	.vop_nrmdir =			tmpfs_nrmdir,
1711 	.vop_nsymlink =			tmpfs_nsymlink,
1712 	.vop_readdir =			tmpfs_readdir,
1713 	.vop_readlink =			tmpfs_readlink,
1714 	.vop_inactive =			tmpfs_inactive,
1715 	.vop_reclaim =			tmpfs_reclaim,
1716 	.vop_print =			tmpfs_print,
1717 	.vop_pathconf =			tmpfs_pathconf,
1718 	.vop_bmap =			tmpfs_bmap,
1719 	.vop_strategy =			tmpfs_strategy,
1720 	.vop_advlock =			tmpfs_advlock,
1721 	.vop_kqfilter =			tmpfs_kqfilter
1722 };
1723