xref: /freebsd/sys/fs/fuse/fuse_vnops.c (revision 8ef24a0d4b28fe230e20637f56869cc4148cd2ca)
1 /*
2  * Copyright (c) 2007-2009 Google Inc. and Amit Singh
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are
7  * met:
8  *
9  * * Redistributions of source code must retain the above copyright
10  *   notice, this list of conditions and the following disclaimer.
11  * * Redistributions in binary form must reproduce the above
12  *   copyright notice, this list of conditions and the following disclaimer
13  *   in the documentation and/or other materials provided with the
14  *   distribution.
15  * * Neither the name of Google Inc. nor the names of its
16  *   contributors may be used to endorse or promote products derived from
17  *   this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  *
31  * Copyright (C) 2005 Csaba Henk.
32  * All rights reserved.
33  *
34  * Redistribution and use in source and binary forms, with or without
35  * modification, are permitted provided that the following conditions
36  * are met:
37  * 1. Redistributions of source code must retain the above copyright
38  *    notice, this list of conditions and the following disclaimer.
39  * 2. Redistributions in binary form must reproduce the above copyright
40  *    notice, this list of conditions and the following disclaimer in the
41  *    documentation and/or other materials provided with the distribution.
42  *
43  * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
44  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
45  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
46  * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
47  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
49  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53  * SUCH DAMAGE.
54  */
55 
56 #include <sys/cdefs.h>
57 __FBSDID("$FreeBSD$");
58 
59 #include <sys/types.h>
60 #include <sys/module.h>
61 #include <sys/systm.h>
62 #include <sys/errno.h>
63 #include <sys/param.h>
64 #include <sys/kernel.h>
65 #include <sys/conf.h>
66 #include <sys/uio.h>
67 #include <sys/malloc.h>
68 #include <sys/queue.h>
69 #include <sys/lock.h>
70 #include <sys/rwlock.h>
71 #include <sys/sx.h>
72 #include <sys/proc.h>
73 #include <sys/mount.h>
74 #include <sys/vnode.h>
75 #include <sys/namei.h>
76 #include <sys/stat.h>
77 #include <sys/unistd.h>
78 #include <sys/filedesc.h>
79 #include <sys/file.h>
80 #include <sys/fcntl.h>
81 #include <sys/dirent.h>
82 #include <sys/bio.h>
83 #include <sys/buf.h>
84 #include <sys/sysctl.h>
85 
86 #include <vm/vm.h>
87 #include <vm/vm_extern.h>
88 #include <vm/pmap.h>
89 #include <vm/vm_map.h>
90 #include <vm/vm_page.h>
91 #include <vm/vm_param.h>
92 #include <vm/vm_object.h>
93 #include <vm/vm_pager.h>
94 #include <vm/vnode_pager.h>
95 #include <vm/vm_object.h>
96 
97 #include "fuse.h"
98 #include "fuse_file.h"
99 #include "fuse_internal.h"
100 #include "fuse_ipc.h"
101 #include "fuse_node.h"
102 #include "fuse_param.h"
103 #include "fuse_io.h"
104 
105 #include <sys/priv.h>
106 
107 #define FUSE_DEBUG_MODULE VNOPS
108 #include "fuse_debug.h"
109 
110 /* vnode ops */
111 static vop_access_t fuse_vnop_access;
112 static vop_close_t fuse_vnop_close;
113 static vop_create_t fuse_vnop_create;
114 static vop_fsync_t fuse_vnop_fsync;
115 static vop_getattr_t fuse_vnop_getattr;
116 static vop_inactive_t fuse_vnop_inactive;
117 static vop_link_t fuse_vnop_link;
118 static vop_lookup_t fuse_vnop_lookup;
119 static vop_mkdir_t fuse_vnop_mkdir;
120 static vop_mknod_t fuse_vnop_mknod;
121 static vop_open_t fuse_vnop_open;
122 static vop_read_t fuse_vnop_read;
123 static vop_readdir_t fuse_vnop_readdir;
124 static vop_readlink_t fuse_vnop_readlink;
125 static vop_reclaim_t fuse_vnop_reclaim;
126 static vop_remove_t fuse_vnop_remove;
127 static vop_rename_t fuse_vnop_rename;
128 static vop_rmdir_t fuse_vnop_rmdir;
129 static vop_setattr_t fuse_vnop_setattr;
130 static vop_strategy_t fuse_vnop_strategy;
131 static vop_symlink_t fuse_vnop_symlink;
132 static vop_write_t fuse_vnop_write;
133 static vop_getpages_t fuse_vnop_getpages;
134 static vop_putpages_t fuse_vnop_putpages;
135 static vop_print_t fuse_vnop_print;
136 
137 struct vop_vector fuse_vnops = {
138 	.vop_default = &default_vnodeops,
139 	.vop_access = fuse_vnop_access,
140 	.vop_close = fuse_vnop_close,
141 	.vop_create = fuse_vnop_create,
142 	.vop_fsync = fuse_vnop_fsync,
143 	.vop_getattr = fuse_vnop_getattr,
144 	.vop_inactive = fuse_vnop_inactive,
145 	.vop_link = fuse_vnop_link,
146 	.vop_lookup = fuse_vnop_lookup,
147 	.vop_mkdir = fuse_vnop_mkdir,
148 	.vop_mknod = fuse_vnop_mknod,
149 	.vop_open = fuse_vnop_open,
150 	.vop_pathconf = vop_stdpathconf,
151 	.vop_read = fuse_vnop_read,
152 	.vop_readdir = fuse_vnop_readdir,
153 	.vop_readlink = fuse_vnop_readlink,
154 	.vop_reclaim = fuse_vnop_reclaim,
155 	.vop_remove = fuse_vnop_remove,
156 	.vop_rename = fuse_vnop_rename,
157 	.vop_rmdir = fuse_vnop_rmdir,
158 	.vop_setattr = fuse_vnop_setattr,
159 	.vop_strategy = fuse_vnop_strategy,
160 	.vop_symlink = fuse_vnop_symlink,
161 	.vop_write = fuse_vnop_write,
162 	.vop_getpages = fuse_vnop_getpages,
163 	.vop_putpages = fuse_vnop_putpages,
164 	.vop_print = fuse_vnop_print,
165 };
166 
167 static u_long fuse_lookup_cache_hits = 0;
168 
169 SYSCTL_ULONG(_vfs_fuse, OID_AUTO, lookup_cache_hits, CTLFLAG_RD,
170     &fuse_lookup_cache_hits, 0, "");
171 
172 static u_long fuse_lookup_cache_misses = 0;
173 
174 SYSCTL_ULONG(_vfs_fuse, OID_AUTO, lookup_cache_misses, CTLFLAG_RD,
175     &fuse_lookup_cache_misses, 0, "");
176 
177 int	fuse_lookup_cache_enable = 1;
178 
179 SYSCTL_INT(_vfs_fuse, OID_AUTO, lookup_cache_enable, CTLFLAG_RW,
180     &fuse_lookup_cache_enable, 0, "");
181 
182 /*
183  * XXX: This feature is highly experimental and can bring to instabilities,
184  * needs revisiting before to be enabled by default.
185  */
186 static int fuse_reclaim_revoked = 0;
187 
188 SYSCTL_INT(_vfs_fuse, OID_AUTO, reclaim_revoked, CTLFLAG_RW,
189     &fuse_reclaim_revoked, 0, "");
190 
191 int	fuse_pbuf_freecnt = -1;
192 
193 #define fuse_vm_page_lock(m)		vm_page_lock((m));
194 #define fuse_vm_page_unlock(m)		vm_page_unlock((m));
195 #define fuse_vm_page_lock_queues()	((void)0)
196 #define fuse_vm_page_unlock_queues()	((void)0)
197 
198 /*
199     struct vnop_access_args {
200         struct vnode *a_vp;
201 #if VOP_ACCESS_TAKES_ACCMODE_T
202         accmode_t a_accmode;
203 #else
204         int a_mode;
205 #endif
206         struct ucred *a_cred;
207         struct thread *a_td;
208     };
209 */
210 static int
211 fuse_vnop_access(struct vop_access_args *ap)
212 {
213 	struct vnode *vp = ap->a_vp;
214 	int accmode = ap->a_accmode;
215 	struct ucred *cred = ap->a_cred;
216 
217 	struct fuse_access_param facp;
218 	struct fuse_data *data = fuse_get_mpdata(vnode_mount(vp));
219 
220 	int err;
221 
222 	FS_DEBUG2G("inode=%ju\n", (uintmax_t)VTOI(vp));
223 
224 	if (fuse_isdeadfs(vp)) {
225 		if (vnode_isvroot(vp)) {
226 			return 0;
227 		}
228 		return ENXIO;
229 	}
230 	if (!(data->dataflags & FSESS_INITED)) {
231 		if (vnode_isvroot(vp)) {
232 			if (priv_check_cred(cred, PRIV_VFS_ADMIN, 0) ||
233 			    (fuse_match_cred(data->daemoncred, cred) == 0)) {
234 				return 0;
235 			}
236 		}
237 		return EBADF;
238 	}
239 	if (vnode_islnk(vp)) {
240 		return 0;
241 	}
242 	bzero(&facp, sizeof(facp));
243 
244 	err = fuse_internal_access(vp, accmode, &facp, ap->a_td, ap->a_cred);
245 	FS_DEBUG2G("err=%d accmode=0x%x\n", err, accmode);
246 	return err;
247 }
248 
249 /*
250     struct vnop_close_args {
251 	struct vnode *a_vp;
252 	int  a_fflag;
253 	struct ucred *a_cred;
254 	struct thread *a_td;
255     };
256 */
257 static int
258 fuse_vnop_close(struct vop_close_args *ap)
259 {
260 	struct vnode *vp = ap->a_vp;
261 	struct ucred *cred = ap->a_cred;
262 	int fflag = ap->a_fflag;
263 	fufh_type_t fufh_type;
264 
265 	fuse_trace_printf_vnop();
266 
267 	if (fuse_isdeadfs(vp)) {
268 		return 0;
269 	}
270 	if (vnode_isdir(vp)) {
271 		if (fuse_filehandle_valid(vp, FUFH_RDONLY)) {
272 			fuse_filehandle_close(vp, FUFH_RDONLY, NULL, cred);
273 		}
274 		return 0;
275 	}
276 	if (fflag & IO_NDELAY) {
277 		return 0;
278 	}
279 	fufh_type = fuse_filehandle_xlate_from_fflags(fflag);
280 
281 	if (!fuse_filehandle_valid(vp, fufh_type)) {
282 		int i;
283 
284 		for (i = 0; i < FUFH_MAXTYPE; i++)
285 			if (fuse_filehandle_valid(vp, i))
286 				break;
287 		if (i == FUFH_MAXTYPE)
288 			panic("FUSE: fufh type %d found to be invalid in close"
289 			      " (fflag=0x%x)\n",
290 			      fufh_type, fflag);
291 	}
292 	if ((VTOFUD(vp)->flag & FN_SIZECHANGE) != 0) {
293 		fuse_vnode_savesize(vp, cred);
294 	}
295 	return 0;
296 }
297 
298 /*
299     struct vnop_create_args {
300 	struct vnode *a_dvp;
301 	struct vnode **a_vpp;
302 	struct componentname *a_cnp;
303 	struct vattr *a_vap;
304     };
305 */
306 static int
307 fuse_vnop_create(struct vop_create_args *ap)
308 {
309 	struct vnode *dvp = ap->a_dvp;
310 	struct vnode **vpp = ap->a_vpp;
311 	struct componentname *cnp = ap->a_cnp;
312 	struct vattr *vap = ap->a_vap;
313 	struct thread *td = cnp->cn_thread;
314 	struct ucred *cred = cnp->cn_cred;
315 
316 	struct fuse_open_in *foi;
317 	struct fuse_entry_out *feo;
318 	struct fuse_dispatcher fdi;
319 	struct fuse_dispatcher *fdip = &fdi;
320 
321 	int err;
322 
323 	struct mount *mp = vnode_mount(dvp);
324 	uint64_t parentnid = VTOFUD(dvp)->nid;
325 	mode_t mode = MAKEIMODE(vap->va_type, vap->va_mode);
326 	uint64_t x_fh_id;
327 	uint32_t x_open_flags;
328 
329 	fuse_trace_printf_vnop();
330 
331 	if (fuse_isdeadfs(dvp)) {
332 		return ENXIO;
333 	}
334 	bzero(&fdi, sizeof(fdi));
335 
336 	/* XXX:	Will we ever want devices ? */
337 	if ((vap->va_type != VREG)) {
338 		MPASS(vap->va_type != VFIFO);
339 		goto bringup;
340 	}
341 	debug_printf("parent nid = %ju, mode = %x\n", (uintmax_t)parentnid,
342 	    mode);
343 
344 	fdisp_init(fdip, sizeof(*foi) + cnp->cn_namelen + 1);
345 	if (!fsess_isimpl(mp, FUSE_CREATE)) {
346 		debug_printf("eh, daemon doesn't implement create?\n");
347 		return (EINVAL);
348 	}
349 	fdisp_make(fdip, FUSE_CREATE, vnode_mount(dvp), parentnid, td, cred);
350 
351 	foi = fdip->indata;
352 	foi->mode = mode;
353 	foi->flags = O_CREAT | O_RDWR;
354 
355 	memcpy((char *)fdip->indata + sizeof(*foi), cnp->cn_nameptr,
356 	    cnp->cn_namelen);
357 	((char *)fdip->indata)[sizeof(*foi) + cnp->cn_namelen] = '\0';
358 
359 	err = fdisp_wait_answ(fdip);
360 
361 	if (err) {
362 		if (err == ENOSYS)
363 			fsess_set_notimpl(mp, FUSE_CREATE);
364 		debug_printf("create: got err=%d from daemon\n", err);
365 		goto out;
366 	}
367 bringup:
368 	feo = fdip->answ;
369 
370 	if ((err = fuse_internal_checkentry(feo, VREG))) {
371 		goto out;
372 	}
373 	err = fuse_vnode_get(mp, feo->nodeid, dvp, vpp, cnp, VREG);
374 	if (err) {
375 		struct fuse_release_in *fri;
376 		uint64_t nodeid = feo->nodeid;
377 		uint64_t fh_id = ((struct fuse_open_out *)(feo + 1))->fh;
378 
379 		fdisp_init(fdip, sizeof(*fri));
380 		fdisp_make(fdip, FUSE_RELEASE, mp, nodeid, td, cred);
381 		fri = fdip->indata;
382 		fri->fh = fh_id;
383 		fri->flags = OFLAGS(mode);
384 		fuse_insert_callback(fdip->tick, fuse_internal_forget_callback);
385 		fuse_insert_message(fdip->tick);
386 		return err;
387 	}
388 	ASSERT_VOP_ELOCKED(*vpp, "fuse_vnop_create");
389 
390 	fdip->answ = feo + 1;
391 
392 	x_fh_id = ((struct fuse_open_out *)(feo + 1))->fh;
393 	x_open_flags = ((struct fuse_open_out *)(feo + 1))->open_flags;
394 	fuse_filehandle_init(*vpp, FUFH_RDWR, NULL, x_fh_id);
395 	fuse_vnode_open(*vpp, x_open_flags, td);
396 	cache_purge_negative(dvp);
397 
398 out:
399 	fdisp_destroy(fdip);
400 	return err;
401 }
402 
403 /*
404  * Our vnop_fsync roughly corresponds to the FUSE_FSYNC method. The Linux
405  * version of FUSE also has a FUSE_FLUSH method.
406  *
407  * On Linux, fsync() synchronizes a file's complete in-core state with that
408  * on disk. The call is not supposed to return until the system has completed
409  * that action or until an error is detected.
410  *
411  * Linux also has an fdatasync() call that is similar to fsync() but is not
412  * required to update the metadata such as access time and modification time.
413  */
414 
415 /*
416     struct vnop_fsync_args {
417 	struct vnodeop_desc *a_desc;
418 	struct vnode * a_vp;
419 	struct ucred * a_cred;
420 	int  a_waitfor;
421 	struct thread * a_td;
422     };
423 */
424 static int
425 fuse_vnop_fsync(struct vop_fsync_args *ap)
426 {
427 	struct vnode *vp = ap->a_vp;
428 	struct thread *td = ap->a_td;
429 
430 	struct fuse_filehandle *fufh;
431 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
432 
433 	int type, err = 0;
434 
435 	fuse_trace_printf_vnop();
436 
437 	if (fuse_isdeadfs(vp)) {
438 		return 0;
439 	}
440 	if ((err = vop_stdfsync(ap)))
441 		return err;
442 
443 	if (!fsess_isimpl(vnode_mount(vp),
444 	    (vnode_vtype(vp) == VDIR ? FUSE_FSYNCDIR : FUSE_FSYNC))) {
445 		goto out;
446 	}
447 	for (type = 0; type < FUFH_MAXTYPE; type++) {
448 		fufh = &(fvdat->fufh[type]);
449 		if (FUFH_IS_VALID(fufh)) {
450 			fuse_internal_fsync(vp, td, NULL, fufh);
451 		}
452 	}
453 
454 out:
455 	return 0;
456 }
457 
458 /*
459     struct vnop_getattr_args {
460 	struct vnode *a_vp;
461 	struct vattr *a_vap;
462 	struct ucred *a_cred;
463 	struct thread *a_td;
464     };
465 */
466 static int
467 fuse_vnop_getattr(struct vop_getattr_args *ap)
468 {
469 	struct vnode *vp = ap->a_vp;
470 	struct vattr *vap = ap->a_vap;
471 	struct ucred *cred = ap->a_cred;
472 	struct thread *td = curthread;
473 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
474 
475 	int err = 0;
476 	int dataflags;
477 	struct fuse_dispatcher fdi;
478 
479 	FS_DEBUG2G("inode=%ju\n", (uintmax_t)VTOI(vp));
480 
481 	dataflags = fuse_get_mpdata(vnode_mount(vp))->dataflags;
482 
483 	/* Note that we are not bailing out on a dead file system just yet. */
484 
485 	if (!(dataflags & FSESS_INITED)) {
486 		if (!vnode_isvroot(vp)) {
487 			fdata_set_dead(fuse_get_mpdata(vnode_mount(vp)));
488 			err = ENOTCONN;
489 			debug_printf("fuse_getattr b: returning ENOTCONN\n");
490 			return err;
491 		} else {
492 			goto fake;
493 		}
494 	}
495 	fdisp_init(&fdi, 0);
496 	if ((err = fdisp_simple_putget_vp(&fdi, FUSE_GETATTR, vp, td, cred))) {
497 		if ((err == ENOTCONN) && vnode_isvroot(vp)) {
498 			/* see comment at similar place in fuse_statfs() */
499 			fdisp_destroy(&fdi);
500 			goto fake;
501 		}
502 		if (err == ENOENT) {
503 			fuse_internal_vnode_disappear(vp);
504 		}
505 		goto out;
506 	}
507 	cache_attrs(vp, (struct fuse_attr_out *)fdi.answ);
508 	if (vap != VTOVA(vp)) {
509 		memcpy(vap, VTOVA(vp), sizeof(*vap));
510 	}
511 	if (vap->va_type != vnode_vtype(vp)) {
512 		fuse_internal_vnode_disappear(vp);
513 		err = ENOENT;
514 		goto out;
515 	}
516 	if ((fvdat->flag & FN_SIZECHANGE) != 0)
517 		vap->va_size = fvdat->filesize;
518 
519 	if (vnode_isreg(vp) && (fvdat->flag & FN_SIZECHANGE) == 0) {
520 		/*
521 	         * This is for those cases when the file size changed without us
522 	         * knowing, and we want to catch up.
523 	         */
524 		off_t new_filesize = ((struct fuse_attr_out *)
525 				      fdi.answ)->attr.size;
526 
527 		if (fvdat->filesize != new_filesize) {
528 			fuse_vnode_setsize(vp, cred, new_filesize);
529 		}
530 	}
531 	debug_printf("fuse_getattr e: returning 0\n");
532 
533 out:
534 	fdisp_destroy(&fdi);
535 	return err;
536 
537 fake:
538 	bzero(vap, sizeof(*vap));
539 	vap->va_type = vnode_vtype(vp);
540 
541 	return 0;
542 }
543 
544 /*
545     struct vnop_inactive_args {
546 	struct vnode *a_vp;
547 	struct thread *a_td;
548     };
549 */
550 static int
551 fuse_vnop_inactive(struct vop_inactive_args *ap)
552 {
553 	struct vnode *vp = ap->a_vp;
554 	struct thread *td = ap->a_td;
555 
556 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
557 	struct fuse_filehandle *fufh = NULL;
558 
559 	int type, need_flush = 1;
560 
561 	FS_DEBUG("inode=%ju\n", (uintmax_t)VTOI(vp));
562 
563 	for (type = 0; type < FUFH_MAXTYPE; type++) {
564 		fufh = &(fvdat->fufh[type]);
565 		if (FUFH_IS_VALID(fufh)) {
566 			if (need_flush && vp->v_type == VREG) {
567 				if ((VTOFUD(vp)->flag & FN_SIZECHANGE) != 0) {
568 					fuse_vnode_savesize(vp, NULL);
569 				}
570 				if (fuse_data_cache_invalidate ||
571 				    (fvdat->flag & FN_REVOKED) != 0)
572 					fuse_io_invalbuf(vp, td);
573 				else
574 					fuse_io_flushbuf(vp, MNT_WAIT, td);
575 				need_flush = 0;
576 			}
577 			fuse_filehandle_close(vp, type, td, NULL);
578 		}
579 	}
580 
581 	if ((fvdat->flag & FN_REVOKED) != 0 && fuse_reclaim_revoked) {
582 		vrecycle(vp);
583 	}
584 	return 0;
585 }
586 
587 /*
588     struct vnop_link_args {
589 	struct vnode *a_tdvp;
590 	struct vnode *a_vp;
591 	struct componentname *a_cnp;
592     };
593 */
594 static int
595 fuse_vnop_link(struct vop_link_args *ap)
596 {
597 	struct vnode *vp = ap->a_vp;
598 	struct vnode *tdvp = ap->a_tdvp;
599 	struct componentname *cnp = ap->a_cnp;
600 
601 	struct vattr *vap = VTOVA(vp);
602 
603 	struct fuse_dispatcher fdi;
604 	struct fuse_entry_out *feo;
605 	struct fuse_link_in fli;
606 
607 	int err;
608 
609 	fuse_trace_printf_vnop();
610 
611 	if (fuse_isdeadfs(vp)) {
612 		return ENXIO;
613 	}
614 	if (vnode_mount(tdvp) != vnode_mount(vp)) {
615 		return EXDEV;
616 	}
617 	if (vap->va_nlink >= FUSE_LINK_MAX) {
618 		return EMLINK;
619 	}
620 	fli.oldnodeid = VTOI(vp);
621 
622 	fdisp_init(&fdi, 0);
623 	fuse_internal_newentry_makerequest(vnode_mount(tdvp), VTOI(tdvp), cnp,
624 	    FUSE_LINK, &fli, sizeof(fli), &fdi);
625 	if ((err = fdisp_wait_answ(&fdi))) {
626 		goto out;
627 	}
628 	feo = fdi.answ;
629 
630 	err = fuse_internal_checkentry(feo, vnode_vtype(vp));
631 out:
632 	fdisp_destroy(&fdi);
633 	return err;
634 }
635 
636 /*
637     struct vnop_lookup_args {
638 	struct vnodeop_desc *a_desc;
639 	struct vnode *a_dvp;
640 	struct vnode **a_vpp;
641 	struct componentname *a_cnp;
642     };
643 */
644 int
645 fuse_vnop_lookup(struct vop_lookup_args *ap)
646 {
647 	struct vnode *dvp = ap->a_dvp;
648 	struct vnode **vpp = ap->a_vpp;
649 	struct componentname *cnp = ap->a_cnp;
650 	struct thread *td = cnp->cn_thread;
651 	struct ucred *cred = cnp->cn_cred;
652 
653 	int nameiop = cnp->cn_nameiop;
654 	int flags = cnp->cn_flags;
655 	int wantparent = flags & (LOCKPARENT | WANTPARENT);
656 	int islastcn = flags & ISLASTCN;
657 	struct mount *mp = vnode_mount(dvp);
658 
659 	int err = 0;
660 	int lookup_err = 0;
661 	struct vnode *vp = NULL;
662 
663 	struct fuse_dispatcher fdi;
664 	enum fuse_opcode op;
665 
666 	uint64_t nid;
667 	struct fuse_access_param facp;
668 
669 	FS_DEBUG2G("parent_inode=%ju - %*s\n",
670 	    (uintmax_t)VTOI(dvp), (int)cnp->cn_namelen, cnp->cn_nameptr);
671 
672 	if (fuse_isdeadfs(dvp)) {
673 		*vpp = NULL;
674 		return ENXIO;
675 	}
676 	if (!vnode_isdir(dvp)) {
677 		return ENOTDIR;
678 	}
679 	if (islastcn && vfs_isrdonly(mp) && (nameiop != LOOKUP)) {
680 		return EROFS;
681 	}
682 	/*
683          * We do access check prior to doing anything else only in the case
684          * when we are at fs root (we'd like to say, "we are at the first
685          * component", but that's not exactly the same... nevermind).
686          * See further comments at further access checks.
687          */
688 
689 	bzero(&facp, sizeof(facp));
690 	if (vnode_isvroot(dvp)) {	/* early permission check hack */
691 		if ((err = fuse_internal_access(dvp, VEXEC, &facp, td, cred))) {
692 			return err;
693 		}
694 	}
695 	if (flags & ISDOTDOT) {
696 		nid = VTOFUD(dvp)->parent_nid;
697 		if (nid == 0) {
698 			return ENOENT;
699 		}
700 		fdisp_init(&fdi, 0);
701 		op = FUSE_GETATTR;
702 		goto calldaemon;
703 	} else if (cnp->cn_namelen == 1 && *(cnp->cn_nameptr) == '.') {
704 		nid = VTOI(dvp);
705 		fdisp_init(&fdi, 0);
706 		op = FUSE_GETATTR;
707 		goto calldaemon;
708 	} else if (fuse_lookup_cache_enable) {
709 		err = cache_lookup(dvp, vpp, cnp, NULL, NULL);
710 		switch (err) {
711 
712 		case -1:		/* positive match */
713 			atomic_add_acq_long(&fuse_lookup_cache_hits, 1);
714 			return 0;
715 
716 		case 0:		/* no match in cache */
717 			atomic_add_acq_long(&fuse_lookup_cache_misses, 1);
718 			break;
719 
720 		case ENOENT:		/* negative match */
721 			/* fall through */
722 		default:
723 			return err;
724 		}
725 	}
726 	nid = VTOI(dvp);
727 	fdisp_init(&fdi, cnp->cn_namelen + 1);
728 	op = FUSE_LOOKUP;
729 
730 calldaemon:
731 	fdisp_make(&fdi, op, mp, nid, td, cred);
732 
733 	if (op == FUSE_LOOKUP) {
734 		memcpy(fdi.indata, cnp->cn_nameptr, cnp->cn_namelen);
735 		((char *)fdi.indata)[cnp->cn_namelen] = '\0';
736 	}
737 	lookup_err = fdisp_wait_answ(&fdi);
738 
739 	if ((op == FUSE_LOOKUP) && !lookup_err) {	/* lookup call succeeded */
740 		nid = ((struct fuse_entry_out *)fdi.answ)->nodeid;
741 		if (!nid) {
742 			/*
743 	                 * zero nodeid is the same as "not found",
744 	                 * but it's also cacheable (which we keep
745 	                 * keep on doing not as of writing this)
746 	                 */
747 			lookup_err = ENOENT;
748 		} else if (nid == FUSE_ROOT_ID) {
749 			lookup_err = EINVAL;
750 		}
751 	}
752 	if (lookup_err &&
753 	    (!fdi.answ_stat || lookup_err != ENOENT || op != FUSE_LOOKUP)) {
754 		fdisp_destroy(&fdi);
755 		return lookup_err;
756 	}
757 	/* lookup_err, if non-zero, must be ENOENT at this point */
758 
759 	if (lookup_err) {
760 
761 		if ((nameiop == CREATE || nameiop == RENAME) && islastcn
762 		     /* && directory dvp has not been removed */ ) {
763 
764 			if (vfs_isrdonly(mp)) {
765 				err = EROFS;
766 				goto out;
767 			}
768 #if 0 /* THINK_ABOUT_THIS */
769 			if ((err = fuse_internal_access(dvp, VWRITE, cred, td, &facp))) {
770 				goto out;
771 			}
772 #endif
773 
774 			/*
775 	                 * Possibly record the position of a slot in the
776 	                 * directory large enough for the new component name.
777 	                 * This can be recorded in the vnode private data for
778 	                 * dvp. Set the SAVENAME flag to hold onto the
779 	                 * pathname for use later in VOP_CREATE or VOP_RENAME.
780 	                 */
781 			cnp->cn_flags |= SAVENAME;
782 
783 			err = EJUSTRETURN;
784 			goto out;
785 		}
786 		/* Consider inserting name into cache. */
787 
788 		/*
789 	         * No we can't use negative caching, as the fs
790 	         * changes are out of our control.
791 	         * False positives' falseness turns out just as things
792 	         * go by, but false negatives' falseness doesn't.
793 	         * (and aiding the caching mechanism with extra control
794 	         * mechanisms comes quite close to beating the whole purpose
795 	         * caching...)
796 	         */
797 #if 0
798 		if ((cnp->cn_flags & MAKEENTRY) != 0) {
799 			FS_DEBUG("inserting NULL into cache\n");
800 			cache_enter(dvp, NULL, cnp);
801 		}
802 #endif
803 		err = ENOENT;
804 		goto out;
805 
806 	} else {
807 
808 		/* !lookup_err */
809 
810 		struct fuse_entry_out *feo = NULL;
811 		struct fuse_attr *fattr = NULL;
812 
813 		if (op == FUSE_GETATTR) {
814 			fattr = &((struct fuse_attr_out *)fdi.answ)->attr;
815 		} else {
816 			feo = (struct fuse_entry_out *)fdi.answ;
817 			fattr = &(feo->attr);
818 		}
819 
820 		/*
821 	         * If deleting, and at end of pathname, return parameters
822 	         * which can be used to remove file.  If the wantparent flag
823 	         * isn't set, we return only the directory, otherwise we go on
824 	         * and lock the inode, being careful with ".".
825 	         */
826 		if (nameiop == DELETE && islastcn) {
827 			/*
828 	                 * Check for write access on directory.
829 	                 */
830 			facp.xuid = fattr->uid;
831 			facp.facc_flags |= FACCESS_STICKY;
832 			err = fuse_internal_access(dvp, VWRITE, &facp, td, cred);
833 			facp.facc_flags &= ~FACCESS_XQUERIES;
834 
835 			if (err) {
836 				goto out;
837 			}
838 			if (nid == VTOI(dvp)) {
839 				vref(dvp);
840 				*vpp = dvp;
841 			} else {
842 				err = fuse_vnode_get(dvp->v_mount, nid, dvp,
843 				    &vp, cnp, IFTOVT(fattr->mode));
844 				if (err)
845 					goto out;
846 				*vpp = vp;
847 			}
848 
849 			/*
850 			 * Save the name for use in VOP_RMDIR and VOP_REMOVE
851 			 * later.
852 			 */
853 			cnp->cn_flags |= SAVENAME;
854 			goto out;
855 
856 		}
857 		/*
858 	         * If rewriting (RENAME), return the inode and the
859 	         * information required to rewrite the present directory
860 	         * Must get inode of directory entry to verify it's a
861 	         * regular file, or empty directory.
862 	         */
863 		if (nameiop == RENAME && wantparent && islastcn) {
864 
865 #if 0 /* THINK_ABOUT_THIS */
866 			if ((err = fuse_internal_access(dvp, VWRITE, cred, td, &facp))) {
867 				goto out;
868 			}
869 #endif
870 
871 			/*
872 	                 * Check for "."
873 	                 */
874 			if (nid == VTOI(dvp)) {
875 				err = EISDIR;
876 				goto out;
877 			}
878 			err = fuse_vnode_get(vnode_mount(dvp),
879 			    nid,
880 			    dvp,
881 			    &vp,
882 			    cnp,
883 			    IFTOVT(fattr->mode));
884 			if (err) {
885 				goto out;
886 			}
887 			*vpp = vp;
888 			/*
889 	                 * Save the name for use in VOP_RENAME later.
890 	                 */
891 			cnp->cn_flags |= SAVENAME;
892 
893 			goto out;
894 		}
895 		if (flags & ISDOTDOT) {
896 			struct mount *mp;
897 			int ltype;
898 
899 			/*
900 			 * Expanded copy of vn_vget_ino() so that
901 			 * fuse_vnode_get() can be used.
902 			 */
903 			mp = dvp->v_mount;
904 			ltype = VOP_ISLOCKED(dvp);
905 			err = vfs_busy(mp, MBF_NOWAIT);
906 			if (err != 0) {
907 				vfs_ref(mp);
908 				VOP_UNLOCK(dvp, 0);
909 				err = vfs_busy(mp, 0);
910 				vn_lock(dvp, ltype | LK_RETRY);
911 				vfs_rel(mp);
912 				if (err)
913 					goto out;
914 				if ((dvp->v_iflag & VI_DOOMED) != 0) {
915 					err = ENOENT;
916 					vfs_unbusy(mp);
917 					goto out;
918 				}
919 			}
920 			VOP_UNLOCK(dvp, 0);
921 			err = fuse_vnode_get(vnode_mount(dvp),
922 			    nid,
923 			    NULL,
924 			    &vp,
925 			    cnp,
926 			    IFTOVT(fattr->mode));
927 			vfs_unbusy(mp);
928 			vn_lock(dvp, ltype | LK_RETRY);
929 			if ((dvp->v_iflag & VI_DOOMED) != 0) {
930 				if (err == 0)
931 					vput(vp);
932 				err = ENOENT;
933 			}
934 			if (err)
935 				goto out;
936 			*vpp = vp;
937 		} else if (nid == VTOI(dvp)) {
938 			vref(dvp);
939 			*vpp = dvp;
940 		} else {
941 			err = fuse_vnode_get(vnode_mount(dvp),
942 			    nid,
943 			    dvp,
944 			    &vp,
945 			    cnp,
946 			    IFTOVT(fattr->mode));
947 			if (err) {
948 				goto out;
949 			}
950 			fuse_vnode_setparent(vp, dvp);
951 			*vpp = vp;
952 		}
953 
954 		if (op == FUSE_GETATTR) {
955 			cache_attrs(*vpp, (struct fuse_attr_out *)fdi.answ);
956 		} else {
957 			cache_attrs(*vpp, (struct fuse_entry_out *)fdi.answ);
958 		}
959 
960 		/* Insert name into cache if appropriate. */
961 
962 		/*
963 	         * Nooo, caching is evil. With caching, we can't avoid stale
964 	         * information taking over the playground (cached info is not
965 	         * just positive/negative, it does have qualitative aspects,
966 	         * too). And a (VOP/FUSE)_GETATTR is always thrown anyway, when
967 	         * walking down along cached path components, and that's not
968 	         * any cheaper than FUSE_LOOKUP. This might change with
969 	         * implementing kernel side attr caching, but... In Linux,
970 	         * lookup results are not cached, and the daemon is bombarded
971 	         * with FUSE_LOOKUPS on and on. This shows that by design, the
972 	         * daemon is expected to handle frequent lookup queries
973 	         * efficiently, do its caching in userspace, and so on.
974 	         *
975 	         * So just leave the name cache alone.
976 	         */
977 
978 		/*
979 	         * Well, now I know, Linux caches lookups, but with a
980 	         * timeout... So it's the same thing as attribute caching:
981 	         * we can deal with it when implement timeouts.
982 	         */
983 #if 0
984 		if (cnp->cn_flags & MAKEENTRY) {
985 			cache_enter(dvp, *vpp, cnp);
986 		}
987 #endif
988 	}
989 out:
990 	if (!lookup_err) {
991 
992 		/* No lookup error; need to clean up. */
993 
994 		if (err) {		/* Found inode; exit with no vnode. */
995 			if (op == FUSE_LOOKUP) {
996 				fuse_internal_forget_send(vnode_mount(dvp), td, cred,
997 				    nid, 1);
998 			}
999 			fdisp_destroy(&fdi);
1000 			return err;
1001 		} else {
1002 #ifndef NO_EARLY_PERM_CHECK_HACK
1003 			if (!islastcn) {
1004 				/*
1005 				 * We have the attributes of the next item
1006 				 * *now*, and it's a fact, and we do not
1007 				 * have to do extra work for it (ie, beg the
1008 				 * daemon), and it neither depends on such
1009 				 * accidental things like attr caching. So
1010 				 * the big idea: check credentials *now*,
1011 				 * not at the beginning of the next call to
1012 				 * lookup.
1013 				 *
1014 				 * The first item of the lookup chain (fs root)
1015 				 * won't be checked then here, of course, as
1016 				 * its never "the next". But go and see that
1017 				 * the root is taken care about at the very
1018 				 * beginning of this function.
1019 				 *
1020 				 * Now, given we want to do the access check
1021 				 * this way, one might ask: so then why not
1022 				 * do the access check just after fetching
1023 				 * the inode and its attributes from the
1024 				 * daemon? Why bother with producing the
1025 				 * corresponding vnode at all if something
1026 				 * is not OK? We know what's the deal as
1027 				 * soon as we get those attrs... There is
1028 				 * one bit of info though not given us by
1029 				 * the daemon: whether his response is
1030 				 * authoritative or not... His response should
1031 				 * be ignored if something is mounted over
1032 				 * the dir in question. But that can be
1033 				 * known only by having the vnode...
1034 				 */
1035 				int tmpvtype = vnode_vtype(*vpp);
1036 
1037 				bzero(&facp, sizeof(facp));
1038 				/*the early perm check hack */
1039 				    facp.facc_flags |= FACCESS_VA_VALID;
1040 
1041 				if ((tmpvtype != VDIR) && (tmpvtype != VLNK)) {
1042 					err = ENOTDIR;
1043 				}
1044 				if (!err && !vnode_mountedhere(*vpp)) {
1045 					err = fuse_internal_access(*vpp, VEXEC, &facp, td, cred);
1046 				}
1047 				if (err) {
1048 					if (tmpvtype == VLNK)
1049 						FS_DEBUG("weird, permission error with a symlink?\n");
1050 					vput(*vpp);
1051 					*vpp = NULL;
1052 				}
1053 			}
1054 #endif
1055 		}
1056 	}
1057 	fdisp_destroy(&fdi);
1058 
1059 	return err;
1060 }
1061 
1062 /*
1063     struct vnop_mkdir_args {
1064 	struct vnode *a_dvp;
1065 	struct vnode **a_vpp;
1066 	struct componentname *a_cnp;
1067 	struct vattr *a_vap;
1068     };
1069 */
1070 static int
1071 fuse_vnop_mkdir(struct vop_mkdir_args *ap)
1072 {
1073 	struct vnode *dvp = ap->a_dvp;
1074 	struct vnode **vpp = ap->a_vpp;
1075 	struct componentname *cnp = ap->a_cnp;
1076 	struct vattr *vap = ap->a_vap;
1077 
1078 	struct fuse_mkdir_in fmdi;
1079 
1080 	fuse_trace_printf_vnop();
1081 
1082 	if (fuse_isdeadfs(dvp)) {
1083 		return ENXIO;
1084 	}
1085 	fmdi.mode = MAKEIMODE(vap->va_type, vap->va_mode);
1086 
1087 	return (fuse_internal_newentry(dvp, vpp, cnp, FUSE_MKDIR, &fmdi,
1088 	    sizeof(fmdi), VDIR));
1089 }
1090 
1091 /*
1092     struct vnop_mknod_args {
1093 	struct vnode *a_dvp;
1094 	struct vnode **a_vpp;
1095 	struct componentname *a_cnp;
1096 	struct vattr *a_vap;
1097     };
1098 */
1099 static int
1100 fuse_vnop_mknod(struct vop_mknod_args *ap)
1101 {
1102 
1103 	return (EINVAL);
1104 }
1105 
1106 
1107 /*
1108     struct vnop_open_args {
1109 	struct vnode *a_vp;
1110 	int  a_mode;
1111 	struct ucred *a_cred;
1112 	struct thread *a_td;
1113 	int a_fdidx; / struct file *a_fp;
1114     };
1115 */
1116 static int
1117 fuse_vnop_open(struct vop_open_args *ap)
1118 {
1119 	struct vnode *vp = ap->a_vp;
1120 	int mode = ap->a_mode;
1121 	struct thread *td = ap->a_td;
1122 	struct ucred *cred = ap->a_cred;
1123 
1124 	fufh_type_t fufh_type;
1125 	struct fuse_vnode_data *fvdat;
1126 
1127 	int error, isdir = 0;
1128 	int32_t fuse_open_flags;
1129 
1130 	FS_DEBUG2G("inode=%ju mode=0x%x\n", (uintmax_t)VTOI(vp), mode);
1131 
1132 	if (fuse_isdeadfs(vp)) {
1133 		return ENXIO;
1134 	}
1135 	fvdat = VTOFUD(vp);
1136 
1137 	if (vnode_isdir(vp)) {
1138 		isdir = 1;
1139 	}
1140 	fuse_open_flags = 0;
1141 	if (isdir) {
1142 		fufh_type = FUFH_RDONLY;
1143 	} else {
1144 		fufh_type = fuse_filehandle_xlate_from_fflags(mode);
1145 		/*
1146 		 * For WRONLY opens, force DIRECT_IO.  This is necessary
1147 		 * since writing a partial block through the buffer cache
1148 		 * will result in a read of the block and that read won't
1149 		 * be allowed by the WRONLY open.
1150 		 */
1151 		if (fufh_type == FUFH_WRONLY ||
1152 		    (fvdat->flag & FN_DIRECTIO) != 0)
1153 			fuse_open_flags = FOPEN_DIRECT_IO;
1154 	}
1155 
1156 	if (fuse_filehandle_validrw(vp, fufh_type) != FUFH_INVALID) {
1157 		fuse_vnode_open(vp, fuse_open_flags, td);
1158 		return 0;
1159 	}
1160 	error = fuse_filehandle_open(vp, fufh_type, NULL, td, cred);
1161 
1162 	return error;
1163 }
1164 
1165 /*
1166     struct vnop_read_args {
1167 	struct vnode *a_vp;
1168 	struct uio *a_uio;
1169 	int  a_ioflag;
1170 	struct ucred *a_cred;
1171     };
1172 */
1173 static int
1174 fuse_vnop_read(struct vop_read_args *ap)
1175 {
1176 	struct vnode *vp = ap->a_vp;
1177 	struct uio *uio = ap->a_uio;
1178 	int ioflag = ap->a_ioflag;
1179 	struct ucred *cred = ap->a_cred;
1180 
1181 	FS_DEBUG2G("inode=%ju offset=%jd resid=%zd\n",
1182 	    (uintmax_t)VTOI(vp), uio->uio_offset, uio->uio_resid);
1183 
1184 	if (fuse_isdeadfs(vp)) {
1185 		return ENXIO;
1186 	}
1187 
1188 	if (VTOFUD(vp)->flag & FN_DIRECTIO) {
1189 		ioflag |= IO_DIRECT;
1190 	}
1191 
1192 	return fuse_io_dispatch(vp, uio, ioflag, cred);
1193 }
1194 
1195 /*
1196     struct vnop_readdir_args {
1197 	struct vnode *a_vp;
1198 	struct uio *a_uio;
1199 	struct ucred *a_cred;
1200 	int *a_eofflag;
1201 	int *ncookies;
1202 	u_long **a_cookies;
1203     };
1204 */
1205 static int
1206 fuse_vnop_readdir(struct vop_readdir_args *ap)
1207 {
1208 	struct vnode *vp = ap->a_vp;
1209 	struct uio *uio = ap->a_uio;
1210 	struct ucred *cred = ap->a_cred;
1211 
1212 	struct fuse_filehandle *fufh = NULL;
1213 	struct fuse_vnode_data *fvdat;
1214 	struct fuse_iov cookediov;
1215 
1216 	int err = 0;
1217 	int freefufh = 0;
1218 
1219 	FS_DEBUG2G("inode=%ju\n", (uintmax_t)VTOI(vp));
1220 
1221 	if (fuse_isdeadfs(vp)) {
1222 		return ENXIO;
1223 	}
1224 	if (				/* XXXIP ((uio_iovcnt(uio) > 1)) || */
1225 	    (uio_resid(uio) < sizeof(struct dirent))) {
1226 		return EINVAL;
1227 	}
1228 	fvdat = VTOFUD(vp);
1229 
1230 	if (!fuse_filehandle_valid(vp, FUFH_RDONLY)) {
1231 		FS_DEBUG("calling readdir() before open()");
1232 		err = fuse_filehandle_open(vp, FUFH_RDONLY, &fufh, NULL, cred);
1233 		freefufh = 1;
1234 	} else {
1235 		err = fuse_filehandle_get(vp, FUFH_RDONLY, &fufh);
1236 	}
1237 	if (err) {
1238 		return (err);
1239 	}
1240 #define DIRCOOKEDSIZE FUSE_DIRENT_ALIGN(FUSE_NAME_OFFSET + MAXNAMLEN + 1)
1241 	fiov_init(&cookediov, DIRCOOKEDSIZE);
1242 
1243 	err = fuse_internal_readdir(vp, uio, fufh, &cookediov);
1244 
1245 	fiov_teardown(&cookediov);
1246 	if (freefufh) {
1247 		fuse_filehandle_close(vp, FUFH_RDONLY, NULL, cred);
1248 	}
1249 	return err;
1250 }
1251 
1252 /*
1253     struct vnop_readlink_args {
1254 	struct vnode *a_vp;
1255 	struct uio *a_uio;
1256 	struct ucred *a_cred;
1257     };
1258 */
1259 static int
1260 fuse_vnop_readlink(struct vop_readlink_args *ap)
1261 {
1262 	struct vnode *vp = ap->a_vp;
1263 	struct uio *uio = ap->a_uio;
1264 	struct ucred *cred = ap->a_cred;
1265 
1266 	struct fuse_dispatcher fdi;
1267 	int err;
1268 
1269 	FS_DEBUG2G("inode=%ju\n", (uintmax_t)VTOI(vp));
1270 
1271 	if (fuse_isdeadfs(vp)) {
1272 		return ENXIO;
1273 	}
1274 	if (!vnode_islnk(vp)) {
1275 		return EINVAL;
1276 	}
1277 	fdisp_init(&fdi, 0);
1278 	err = fdisp_simple_putget_vp(&fdi, FUSE_READLINK, vp, curthread, cred);
1279 	if (err) {
1280 		goto out;
1281 	}
1282 	if (((char *)fdi.answ)[0] == '/' &&
1283 	    fuse_get_mpdata(vnode_mount(vp))->dataflags & FSESS_PUSH_SYMLINKS_IN) {
1284 		char *mpth = vnode_mount(vp)->mnt_stat.f_mntonname;
1285 
1286 		err = uiomove(mpth, strlen(mpth), uio);
1287 	}
1288 	if (!err) {
1289 		err = uiomove(fdi.answ, fdi.iosize, uio);
1290 	}
1291 out:
1292 	fdisp_destroy(&fdi);
1293 	return err;
1294 }
1295 
1296 /*
1297     struct vnop_reclaim_args {
1298 	struct vnode *a_vp;
1299 	struct thread *a_td;
1300     };
1301 */
1302 static int
1303 fuse_vnop_reclaim(struct vop_reclaim_args *ap)
1304 {
1305 	struct vnode *vp = ap->a_vp;
1306 	struct thread *td = ap->a_td;
1307 
1308 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
1309 	struct fuse_filehandle *fufh = NULL;
1310 
1311 	int type;
1312 
1313 	if (!fvdat) {
1314 		panic("FUSE: no vnode data during recycling");
1315 	}
1316 	FS_DEBUG("inode=%ju\n", (uintmax_t)VTOI(vp));
1317 
1318 	for (type = 0; type < FUFH_MAXTYPE; type++) {
1319 		fufh = &(fvdat->fufh[type]);
1320 		if (FUFH_IS_VALID(fufh)) {
1321 			printf("FUSE: vnode being reclaimed but fufh (type=%d) is valid",
1322 			    type);
1323 			fuse_filehandle_close(vp, type, td, NULL);
1324 		}
1325 	}
1326 
1327 	if ((!fuse_isdeadfs(vp)) && (fvdat->nlookup)) {
1328 		fuse_internal_forget_send(vnode_mount(vp), td, NULL, VTOI(vp),
1329 		    fvdat->nlookup);
1330 	}
1331 	fuse_vnode_setparent(vp, NULL);
1332 	cache_purge(vp);
1333 	vfs_hash_remove(vp);
1334 	vnode_destroy_vobject(vp);
1335 	fuse_vnode_destroy(vp);
1336 
1337 	return 0;
1338 }
1339 
1340 /*
1341     struct vnop_remove_args {
1342 	struct vnode *a_dvp;
1343 	struct vnode *a_vp;
1344 	struct componentname *a_cnp;
1345     };
1346 */
1347 static int
1348 fuse_vnop_remove(struct vop_remove_args *ap)
1349 {
1350 	struct vnode *dvp = ap->a_dvp;
1351 	struct vnode *vp = ap->a_vp;
1352 	struct componentname *cnp = ap->a_cnp;
1353 
1354 	int err;
1355 
1356 	FS_DEBUG2G("inode=%ju name=%*s\n",
1357 	    (uintmax_t)VTOI(vp), (int)cnp->cn_namelen, cnp->cn_nameptr);
1358 
1359 	if (fuse_isdeadfs(vp)) {
1360 		return ENXIO;
1361 	}
1362 	if (vnode_isdir(vp)) {
1363 		return EPERM;
1364 	}
1365 	cache_purge(vp);
1366 
1367 	err = fuse_internal_remove(dvp, vp, cnp, FUSE_UNLINK);
1368 
1369 	if (err == 0)
1370 		fuse_internal_vnode_disappear(vp);
1371 	return err;
1372 }
1373 
1374 /*
1375     struct vnop_rename_args {
1376 	struct vnode *a_fdvp;
1377 	struct vnode *a_fvp;
1378 	struct componentname *a_fcnp;
1379 	struct vnode *a_tdvp;
1380 	struct vnode *a_tvp;
1381 	struct componentname *a_tcnp;
1382     };
1383 */
1384 static int
1385 fuse_vnop_rename(struct vop_rename_args *ap)
1386 {
1387 	struct vnode *fdvp = ap->a_fdvp;
1388 	struct vnode *fvp = ap->a_fvp;
1389 	struct componentname *fcnp = ap->a_fcnp;
1390 	struct vnode *tdvp = ap->a_tdvp;
1391 	struct vnode *tvp = ap->a_tvp;
1392 	struct componentname *tcnp = ap->a_tcnp;
1393 	struct fuse_data *data;
1394 
1395 	int err = 0;
1396 
1397 	FS_DEBUG2G("from: inode=%ju name=%*s -> to: inode=%ju name=%*s\n",
1398 	    (uintmax_t)VTOI(fvp), (int)fcnp->cn_namelen, fcnp->cn_nameptr,
1399 	    (uintmax_t)(tvp == NULL ? -1 : VTOI(tvp)),
1400 	    (int)tcnp->cn_namelen, tcnp->cn_nameptr);
1401 
1402 	if (fuse_isdeadfs(fdvp)) {
1403 		return ENXIO;
1404 	}
1405 	if (fvp->v_mount != tdvp->v_mount ||
1406 	    (tvp && fvp->v_mount != tvp->v_mount)) {
1407 		FS_DEBUG("cross-device rename: %s -> %s\n",
1408 		    fcnp->cn_nameptr, (tcnp != NULL ? tcnp->cn_nameptr : "(NULL)"));
1409 		err = EXDEV;
1410 		goto out;
1411 	}
1412 	cache_purge(fvp);
1413 
1414 	/*
1415          * FUSE library is expected to check if target directory is not
1416          * under the source directory in the file system tree.
1417          * Linux performs this check at VFS level.
1418          */
1419 	data = fuse_get_mpdata(vnode_mount(tdvp));
1420 	sx_xlock(&data->rename_lock);
1421 	err = fuse_internal_rename(fdvp, fcnp, tdvp, tcnp);
1422 	if (err == 0) {
1423 		if (tdvp != fdvp)
1424 			fuse_vnode_setparent(fvp, tdvp);
1425 		if (tvp != NULL)
1426 			fuse_vnode_setparent(tvp, NULL);
1427 	}
1428 	sx_unlock(&data->rename_lock);
1429 
1430 	if (tvp != NULL && tvp != fvp) {
1431 		cache_purge(tvp);
1432 	}
1433 	if (vnode_isdir(fvp)) {
1434 		if ((tvp != NULL) && vnode_isdir(tvp)) {
1435 			cache_purge(tdvp);
1436 		}
1437 		cache_purge(fdvp);
1438 	}
1439 out:
1440 	if (tdvp == tvp) {
1441 		vrele(tdvp);
1442 	} else {
1443 		vput(tdvp);
1444 	}
1445 	if (tvp != NULL) {
1446 		vput(tvp);
1447 	}
1448 	vrele(fdvp);
1449 	vrele(fvp);
1450 
1451 	return err;
1452 }
1453 
1454 /*
1455     struct vnop_rmdir_args {
1456 	    struct vnode *a_dvp;
1457 	    struct vnode *a_vp;
1458 	    struct componentname *a_cnp;
1459     } *ap;
1460 */
1461 static int
1462 fuse_vnop_rmdir(struct vop_rmdir_args *ap)
1463 {
1464 	struct vnode *dvp = ap->a_dvp;
1465 	struct vnode *vp = ap->a_vp;
1466 
1467 	int err;
1468 
1469 	FS_DEBUG2G("inode=%ju\n", (uintmax_t)VTOI(vp));
1470 
1471 	if (fuse_isdeadfs(vp)) {
1472 		return ENXIO;
1473 	}
1474 	if (VTOFUD(vp) == VTOFUD(dvp)) {
1475 		return EINVAL;
1476 	}
1477 	err = fuse_internal_remove(dvp, vp, ap->a_cnp, FUSE_RMDIR);
1478 
1479 	if (err == 0)
1480 		fuse_internal_vnode_disappear(vp);
1481 	return err;
1482 }
1483 
1484 /*
1485     struct vnop_setattr_args {
1486 	struct vnode *a_vp;
1487 	struct vattr *a_vap;
1488 	struct ucred *a_cred;
1489 	struct thread *a_td;
1490     };
1491 */
1492 static int
1493 fuse_vnop_setattr(struct vop_setattr_args *ap)
1494 {
1495 	struct vnode *vp = ap->a_vp;
1496 	struct vattr *vap = ap->a_vap;
1497 	struct ucred *cred = ap->a_cred;
1498 	struct thread *td = curthread;
1499 
1500 	struct fuse_dispatcher fdi;
1501 	struct fuse_setattr_in *fsai;
1502 	struct fuse_access_param facp;
1503 
1504 	int err = 0;
1505 	enum vtype vtyp;
1506 	int sizechanged = 0;
1507 	uint64_t newsize = 0;
1508 
1509 	FS_DEBUG2G("inode=%ju\n", (uintmax_t)VTOI(vp));
1510 
1511 	if (fuse_isdeadfs(vp)) {
1512 		return ENXIO;
1513 	}
1514 	fdisp_init(&fdi, sizeof(*fsai));
1515 	fdisp_make_vp(&fdi, FUSE_SETATTR, vp, td, cred);
1516 	fsai = fdi.indata;
1517 	fsai->valid = 0;
1518 
1519 	bzero(&facp, sizeof(facp));
1520 
1521 	facp.xuid = vap->va_uid;
1522 	facp.xgid = vap->va_gid;
1523 
1524 	if (vap->va_uid != (uid_t)VNOVAL) {
1525 		facp.facc_flags |= FACCESS_CHOWN;
1526 		fsai->uid = vap->va_uid;
1527 		fsai->valid |= FATTR_UID;
1528 	}
1529 	if (vap->va_gid != (gid_t)VNOVAL) {
1530 		facp.facc_flags |= FACCESS_CHOWN;
1531 		fsai->gid = vap->va_gid;
1532 		fsai->valid |= FATTR_GID;
1533 	}
1534 	if (vap->va_size != VNOVAL) {
1535 
1536 		struct fuse_filehandle *fufh = NULL;
1537 
1538 		/*Truncate to a new value. */
1539 		    fsai->size = vap->va_size;
1540 		sizechanged = 1;
1541 		newsize = vap->va_size;
1542 		fsai->valid |= FATTR_SIZE;
1543 
1544 		fuse_filehandle_getrw(vp, FUFH_WRONLY, &fufh);
1545 		if (fufh) {
1546 			fsai->fh = fufh->fh_id;
1547 			fsai->valid |= FATTR_FH;
1548 		}
1549 	}
1550 	if (vap->va_atime.tv_sec != VNOVAL) {
1551 		fsai->atime = vap->va_atime.tv_sec;
1552 		fsai->atimensec = vap->va_atime.tv_nsec;
1553 		fsai->valid |= FATTR_ATIME;
1554 	}
1555 	if (vap->va_mtime.tv_sec != VNOVAL) {
1556 		fsai->mtime = vap->va_mtime.tv_sec;
1557 		fsai->mtimensec = vap->va_mtime.tv_nsec;
1558 		fsai->valid |= FATTR_MTIME;
1559 	}
1560 	if (vap->va_mode != (mode_t)VNOVAL) {
1561 		fsai->mode = vap->va_mode & ALLPERMS;
1562 		fsai->valid |= FATTR_MODE;
1563 	}
1564 	if (!fsai->valid) {
1565 		goto out;
1566 	}
1567 	vtyp = vnode_vtype(vp);
1568 
1569 	if (fsai->valid & FATTR_SIZE && vtyp == VDIR) {
1570 		err = EISDIR;
1571 		goto out;
1572 	}
1573 	if (vfs_isrdonly(vnode_mount(vp)) && (fsai->valid & ~FATTR_SIZE || vtyp == VREG)) {
1574 		err = EROFS;
1575 		goto out;
1576 	}
1577 	if (fsai->valid & ~FATTR_SIZE) {
1578 	  /*err = fuse_internal_access(vp, VADMIN, context, &facp); */
1579 	  /*XXX */
1580 		    err = 0;
1581 	}
1582 	facp.facc_flags &= ~FACCESS_XQUERIES;
1583 
1584 	if (err && !(fsai->valid & ~(FATTR_ATIME | FATTR_MTIME)) &&
1585 	    vap->va_vaflags & VA_UTIMES_NULL) {
1586 		err = fuse_internal_access(vp, VWRITE, &facp, td, cred);
1587 	}
1588 	if (err)
1589 		goto out;
1590 	if ((err = fdisp_wait_answ(&fdi)))
1591 		goto out;
1592 	vtyp = IFTOVT(((struct fuse_attr_out *)fdi.answ)->attr.mode);
1593 
1594 	if (vnode_vtype(vp) != vtyp) {
1595 		if (vnode_vtype(vp) == VNON && vtyp != VNON) {
1596 			debug_printf("FUSE: Dang! vnode_vtype is VNON and vtype isn't.\n");
1597 		} else {
1598 			/*
1599 	                 * STALE vnode, ditch
1600 	                 *
1601 	                 * The vnode has changed its type "behind our back". There's
1602 	                 * nothing really we can do, so let us just force an internal
1603 	                 * revocation and tell the caller to try again, if interested.
1604 	                 */
1605 			fuse_internal_vnode_disappear(vp);
1606 			err = EAGAIN;
1607 		}
1608 	}
1609 	if (!err && !sizechanged) {
1610 		cache_attrs(vp, (struct fuse_attr_out *)fdi.answ);
1611 	}
1612 out:
1613 	fdisp_destroy(&fdi);
1614 	if (!err && sizechanged) {
1615 		fuse_vnode_setsize(vp, cred, newsize);
1616 		VTOFUD(vp)->flag &= ~FN_SIZECHANGE;
1617 	}
1618 	return err;
1619 }
1620 
1621 /*
1622     struct vnop_strategy_args {
1623 	struct vnode *a_vp;
1624 	struct buf *a_bp;
1625     };
1626 */
1627 static int
1628 fuse_vnop_strategy(struct vop_strategy_args *ap)
1629 {
1630 	struct vnode *vp = ap->a_vp;
1631 	struct buf *bp = ap->a_bp;
1632 
1633 	fuse_trace_printf_vnop();
1634 
1635 	if (!vp || fuse_isdeadfs(vp)) {
1636 		bp->b_ioflags |= BIO_ERROR;
1637 		bp->b_error = ENXIO;
1638 		bufdone(bp);
1639 		return ENXIO;
1640 	}
1641 	if (bp->b_iocmd == BIO_WRITE)
1642 		fuse_vnode_refreshsize(vp, NOCRED);
1643 
1644 	(void)fuse_io_strategy(vp, bp);
1645 
1646 	/*
1647 	 * This is a dangerous function. If returns error, that might mean a
1648 	 * panic. We prefer pretty much anything over being forced to panic
1649 	 * by a malicious daemon (a demon?). So we just return 0 anyway. You
1650 	 * should never mind this: this function has its own error
1651 	 * propagation mechanism via the argument buffer, so
1652 	 * not-that-melodramatic residents of the call chain still will be
1653 	 * able to know what to do.
1654 	 */
1655 	return 0;
1656 }
1657 
1658 
1659 /*
1660     struct vnop_symlink_args {
1661 	struct vnode *a_dvp;
1662 	struct vnode **a_vpp;
1663 	struct componentname *a_cnp;
1664 	struct vattr *a_vap;
1665 	char *a_target;
1666     };
1667 */
1668 static int
1669 fuse_vnop_symlink(struct vop_symlink_args *ap)
1670 {
1671 	struct vnode *dvp = ap->a_dvp;
1672 	struct vnode **vpp = ap->a_vpp;
1673 	struct componentname *cnp = ap->a_cnp;
1674 	char *target = ap->a_target;
1675 
1676 	struct fuse_dispatcher fdi;
1677 
1678 	int err;
1679 	size_t len;
1680 
1681 	FS_DEBUG2G("inode=%ju name=%*s\n",
1682 	    (uintmax_t)VTOI(dvp), (int)cnp->cn_namelen, cnp->cn_nameptr);
1683 
1684 	if (fuse_isdeadfs(dvp)) {
1685 		return ENXIO;
1686 	}
1687 	/*
1688          * Unlike the other creator type calls, here we have to create a message
1689          * where the name of the new entry comes first, and the data describing
1690          * the entry comes second.
1691          * Hence we can't rely on our handy fuse_internal_newentry() routine,
1692          * but put together the message manually and just call the core part.
1693          */
1694 
1695 	len = strlen(target) + 1;
1696 	fdisp_init(&fdi, len + cnp->cn_namelen + 1);
1697 	fdisp_make_vp(&fdi, FUSE_SYMLINK, dvp, curthread, NULL);
1698 
1699 	memcpy(fdi.indata, cnp->cn_nameptr, cnp->cn_namelen);
1700 	((char *)fdi.indata)[cnp->cn_namelen] = '\0';
1701 	memcpy((char *)fdi.indata + cnp->cn_namelen + 1, target, len);
1702 
1703 	err = fuse_internal_newentry_core(dvp, vpp, cnp, VLNK, &fdi);
1704 	fdisp_destroy(&fdi);
1705 	return err;
1706 }
1707 
1708 /*
1709     struct vnop_write_args {
1710 	struct vnode *a_vp;
1711 	struct uio *a_uio;
1712 	int  a_ioflag;
1713 	struct ucred *a_cred;
1714     };
1715 */
1716 static int
1717 fuse_vnop_write(struct vop_write_args *ap)
1718 {
1719 	struct vnode *vp = ap->a_vp;
1720 	struct uio *uio = ap->a_uio;
1721 	int ioflag = ap->a_ioflag;
1722 	struct ucred *cred = ap->a_cred;
1723 
1724 	fuse_trace_printf_vnop();
1725 
1726 	if (fuse_isdeadfs(vp)) {
1727 		return ENXIO;
1728 	}
1729 	fuse_vnode_refreshsize(vp, cred);
1730 
1731 	if (VTOFUD(vp)->flag & FN_DIRECTIO) {
1732 		ioflag |= IO_DIRECT;
1733 	}
1734 
1735 	return fuse_io_dispatch(vp, uio, ioflag, cred);
1736 }
1737 
1738 /*
1739     struct vnop_getpages_args {
1740         struct vnode *a_vp;
1741         vm_page_t *a_m;
1742         int a_count;
1743         int a_reqpage;
1744     };
1745 */
1746 static int
1747 fuse_vnop_getpages(struct vop_getpages_args *ap)
1748 {
1749 	int i, error, nextoff, size, toff, count, npages;
1750 	struct uio uio;
1751 	struct iovec iov;
1752 	vm_offset_t kva;
1753 	struct buf *bp;
1754 	struct vnode *vp;
1755 	struct thread *td;
1756 	struct ucred *cred;
1757 	vm_page_t *pages;
1758 
1759 	FS_DEBUG2G("heh\n");
1760 
1761 	vp = ap->a_vp;
1762 	KASSERT(vp->v_object, ("objectless vp passed to getpages"));
1763 	td = curthread;			/* XXX */
1764 	cred = curthread->td_ucred;	/* XXX */
1765 	pages = ap->a_m;
1766 	npages = ap->a_count;
1767 
1768 	if (!fsess_opt_mmap(vnode_mount(vp))) {
1769 		FS_DEBUG("called on non-cacheable vnode??\n");
1770 		return (VM_PAGER_ERROR);
1771 	}
1772 
1773 	/*
1774 	 * If the last page is partially valid, just return it and allow
1775 	 * the pager to zero-out the blanks.  Partially valid pages can
1776 	 * only occur at the file EOF.
1777 	 *
1778 	 * XXXGL: is that true for FUSE, which is a local filesystem,
1779 	 * but still somewhat disconnected from the kernel?
1780 	 */
1781 	VM_OBJECT_WLOCK(vp->v_object);
1782 	if (pages[npages - 1]->valid != 0 && --npages == 0)
1783 		goto out;
1784 	VM_OBJECT_WUNLOCK(vp->v_object);
1785 
1786 	/*
1787 	 * We use only the kva address for the buffer, but this is extremely
1788 	 * convenient and fast.
1789 	 */
1790 	bp = getpbuf(&fuse_pbuf_freecnt);
1791 
1792 	kva = (vm_offset_t)bp->b_data;
1793 	pmap_qenter(kva, pages, npages);
1794 	PCPU_INC(cnt.v_vnodein);
1795 	PCPU_ADD(cnt.v_vnodepgsin, npages);
1796 
1797 	count = npages << PAGE_SHIFT;
1798 	iov.iov_base = (caddr_t)kva;
1799 	iov.iov_len = count;
1800 	uio.uio_iov = &iov;
1801 	uio.uio_iovcnt = 1;
1802 	uio.uio_offset = IDX_TO_OFF(pages[0]->pindex);
1803 	uio.uio_resid = count;
1804 	uio.uio_segflg = UIO_SYSSPACE;
1805 	uio.uio_rw = UIO_READ;
1806 	uio.uio_td = td;
1807 
1808 	error = fuse_io_dispatch(vp, &uio, IO_DIRECT, cred);
1809 	pmap_qremove(kva, npages);
1810 
1811 	relpbuf(bp, &fuse_pbuf_freecnt);
1812 
1813 	if (error && (uio.uio_resid == count)) {
1814 		FS_DEBUG("error %d\n", error);
1815 		return VM_PAGER_ERROR;
1816 	}
1817 	/*
1818 	 * Calculate the number of bytes read and validate only that number
1819 	 * of bytes.  Note that due to pending writes, size may be 0.  This
1820 	 * does not mean that the remaining data is invalid!
1821 	 */
1822 
1823 	size = count - uio.uio_resid;
1824 	VM_OBJECT_WLOCK(vp->v_object);
1825 	fuse_vm_page_lock_queues();
1826 	for (i = 0, toff = 0; i < npages; i++, toff = nextoff) {
1827 		vm_page_t m;
1828 
1829 		nextoff = toff + PAGE_SIZE;
1830 		m = pages[i];
1831 
1832 		if (nextoff <= size) {
1833 			/*
1834 			 * Read operation filled an entire page
1835 			 */
1836 			m->valid = VM_PAGE_BITS_ALL;
1837 			KASSERT(m->dirty == 0,
1838 			    ("fuse_getpages: page %p is dirty", m));
1839 		} else if (size > toff) {
1840 			/*
1841 			 * Read operation filled a partial page.
1842 			 */
1843 			m->valid = 0;
1844 			vm_page_set_valid_range(m, 0, size - toff);
1845 			KASSERT(m->dirty == 0,
1846 			    ("fuse_getpages: page %p is dirty", m));
1847 		} else {
1848 			/*
1849 			 * Read operation was short.  If no error occurred
1850 			 * we may have hit a zero-fill section.   We simply
1851 			 * leave valid set to 0.
1852 			 */
1853 			;
1854 		}
1855 	}
1856 	fuse_vm_page_unlock_queues();
1857 out:
1858 	VM_OBJECT_WUNLOCK(vp->v_object);
1859 	if (ap->a_rbehind)
1860 		*ap->a_rbehind = 0;
1861 	if (ap->a_rahead)
1862 		*ap->a_rahead = 0;
1863 	return (VM_PAGER_OK);
1864 }
1865 
1866 /*
1867     struct vnop_putpages_args {
1868         struct vnode *a_vp;
1869         vm_page_t *a_m;
1870         int a_count;
1871         int a_sync;
1872         int *a_rtvals;
1873         vm_ooffset_t a_offset;
1874     };
1875 */
1876 static int
1877 fuse_vnop_putpages(struct vop_putpages_args *ap)
1878 {
1879 	struct uio uio;
1880 	struct iovec iov;
1881 	vm_offset_t kva;
1882 	struct buf *bp;
1883 	int i, error, npages, count;
1884 	off_t offset;
1885 	int *rtvals;
1886 	struct vnode *vp;
1887 	struct thread *td;
1888 	struct ucred *cred;
1889 	vm_page_t *pages;
1890 	vm_ooffset_t fsize;
1891 
1892 	FS_DEBUG2G("heh\n");
1893 
1894 	vp = ap->a_vp;
1895 	KASSERT(vp->v_object, ("objectless vp passed to putpages"));
1896 	fsize = vp->v_object->un_pager.vnp.vnp_size;
1897 	td = curthread;			/* XXX */
1898 	cred = curthread->td_ucred;	/* XXX */
1899 	pages = ap->a_m;
1900 	count = ap->a_count;
1901 	rtvals = ap->a_rtvals;
1902 	npages = btoc(count);
1903 	offset = IDX_TO_OFF(pages[0]->pindex);
1904 
1905 	if (!fsess_opt_mmap(vnode_mount(vp))) {
1906 		FS_DEBUG("called on non-cacheable vnode??\n");
1907 	}
1908 	for (i = 0; i < npages; i++)
1909 		rtvals[i] = VM_PAGER_AGAIN;
1910 
1911 	/*
1912 	 * When putting pages, do not extend file past EOF.
1913 	 */
1914 
1915 	if (offset + count > fsize) {
1916 		count = fsize - offset;
1917 		if (count < 0)
1918 			count = 0;
1919 	}
1920 	/*
1921 	 * We use only the kva address for the buffer, but this is extremely
1922 	 * convenient and fast.
1923 	 */
1924 	bp = getpbuf(&fuse_pbuf_freecnt);
1925 
1926 	kva = (vm_offset_t)bp->b_data;
1927 	pmap_qenter(kva, pages, npages);
1928 	PCPU_INC(cnt.v_vnodeout);
1929 	PCPU_ADD(cnt.v_vnodepgsout, count);
1930 
1931 	iov.iov_base = (caddr_t)kva;
1932 	iov.iov_len = count;
1933 	uio.uio_iov = &iov;
1934 	uio.uio_iovcnt = 1;
1935 	uio.uio_offset = offset;
1936 	uio.uio_resid = count;
1937 	uio.uio_segflg = UIO_SYSSPACE;
1938 	uio.uio_rw = UIO_WRITE;
1939 	uio.uio_td = td;
1940 
1941 	error = fuse_io_dispatch(vp, &uio, IO_DIRECT, cred);
1942 
1943 	pmap_qremove(kva, npages);
1944 	relpbuf(bp, &fuse_pbuf_freecnt);
1945 
1946 	if (!error) {
1947 		int nwritten = round_page(count - uio.uio_resid) / PAGE_SIZE;
1948 
1949 		for (i = 0; i < nwritten; i++) {
1950 			rtvals[i] = VM_PAGER_OK;
1951 			VM_OBJECT_WLOCK(pages[i]->object);
1952 			vm_page_undirty(pages[i]);
1953 			VM_OBJECT_WUNLOCK(pages[i]->object);
1954 		}
1955 	}
1956 	return rtvals[0];
1957 }
1958 
1959 /*
1960     struct vnop_print_args {
1961         struct vnode *a_vp;
1962     };
1963 */
1964 static int
1965 fuse_vnop_print(struct vop_print_args *ap)
1966 {
1967 	struct fuse_vnode_data *fvdat = VTOFUD(ap->a_vp);
1968 
1969 	printf("nodeid: %ju, parent nodeid: %ju, nlookup: %ju, flag: %#x\n",
1970 	    (uintmax_t)VTOILLU(ap->a_vp), (uintmax_t)fvdat->parent_nid,
1971 	    (uintmax_t)fvdat->nlookup,
1972 	    fvdat->flag);
1973 
1974 	return 0;
1975 }
1976