xref: /openbsd/sys/kern/vfs_vops.c (revision 09467b48)
1 /*	$OpenBSD: vfs_vops.c,v 1.28 2020/04/08 08:07:51 mpi Exp $	*/
2 /*
3  * Copyright (c) 2010 Thordur I. Bjornsson <thib@openbsd.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  *
17  * Copyright (c) 1992, 1993
18  *	The Regents of the University of California.  All rights reserved.
19  *
20  * Redistribution and use in source and binary forms, with or without
21  * modification, are permitted provided that the following conditions
22  * are met:
23  * 1. Redistributions of source code must retain the above copyright
24  *    notice, this list of conditions and the following disclaimer.
25  * 2. Redistributions in binary form must reproduce the above copyright
26  *    notice, this list of conditions and the following disclaimer in the
27  *    documentation and/or other materials provided with the distribution.
28  * 3. Neither the name of the University nor the names of its contributors
29  *    may be used to endorse or promote products derived from this software
30  *    without specific prior written permission.
31  *
32  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS AS IS'' AND
33  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
34  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
35  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
36  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
40  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
41  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
42  * SUCH DAMAGE.
43  */
44 
45 #include <sys/param.h>
46 #include <sys/vnode.h>
47 #include <sys/unistd.h>
48 #include <sys/systm.h>
49 
50 #ifdef VFSLCKDEBUG
51 #include <sys/systm.h>		/* for panic() */
52 
53 #define ASSERT_VP_ISLOCKED(vp) do {				\
54 	if (((vp)->v_flag & VLOCKSWORK) && !VOP_ISLOCKED(vp)) {	\
55 		VOP_PRINT(vp);					\
56 		panic("vp not locked");				\
57 	}							\
58 } while (0)
59 #else
60 #define ASSERT_VP_ISLOCKED(vp)  /* nothing */
61 #endif
62 
63 int
64 VOP_ISLOCKED(struct vnode *vp)
65 {
66 	struct vop_islocked_args a;
67 	a.a_vp = vp;
68 
69 	if (vp->v_op->vop_islocked == NULL)
70 		return (EOPNOTSUPP);
71 
72 	return ((vp->v_op->vop_islocked)(&a));
73 }
74 
75 int
76 VOP_LOOKUP(struct vnode *dvp, struct vnode **vpp,
77     struct componentname *cnp)
78 {
79 	int r;
80 	struct vop_lookup_args a;
81 	a.a_dvp = dvp;
82 	a.a_vpp = vpp;
83 	a.a_cnp = cnp;
84 
85 	if (dvp->v_op->vop_lookup == NULL)
86 		return (EOPNOTSUPP);
87 
88 	dvp->v_inflight++;
89 	r = (dvp->v_op->vop_lookup)(&a);
90 	dvp->v_inflight--;
91 	return r;
92 }
93 
94 int
95 VOP_CREATE(struct vnode *dvp, struct vnode **vpp,
96     struct componentname *cnp, struct vattr *vap)
97 {
98 	int r;
99 	struct vop_create_args a;
100 	a.a_dvp = dvp;
101 	a.a_vpp = vpp;
102 	a.a_cnp = cnp;
103 	a.a_vap = vap;
104 
105 	ASSERT_VP_ISLOCKED(dvp);
106 
107 	if (dvp->v_op->vop_create == NULL)
108 		return (EOPNOTSUPP);
109 
110 	dvp->v_inflight++;
111 	r = (dvp->v_op->vop_create)(&a);
112 	dvp->v_inflight--;
113 	return r;
114 }
115 
116 int
117 VOP_MKNOD(struct vnode *dvp, struct vnode **vpp,
118     struct componentname *cnp, struct vattr *vap)
119 {
120 	int r;
121 	struct vop_mknod_args a;
122 	a.a_dvp = dvp;
123 	a.a_vpp = vpp;
124 	a.a_cnp = cnp;
125 	a.a_vap = vap;
126 
127 	ASSERT_VP_ISLOCKED(dvp);
128 
129 	if (dvp->v_op->vop_mknod == NULL)
130 		return (EOPNOTSUPP);
131 
132 	dvp->v_inflight++;
133 	r = (dvp->v_op->vop_mknod)(&a);
134 	dvp->v_inflight--;
135 	return r;
136 }
137 
138 int
139 VOP_OPEN(struct vnode *vp, int mode, struct ucred *cred, struct proc *p)
140 {
141 	int r;
142 	struct vop_open_args a;
143 	a.a_vp = vp;
144 	a.a_mode = mode;
145 	a.a_cred = cred;
146 	a.a_p = p;
147 
148 	if (vp->v_op->vop_open == NULL)
149 		return (EOPNOTSUPP);
150 
151 	vp->v_inflight++;
152 	r = (vp->v_op->vop_open)(&a);
153 	vp->v_inflight--;
154 	return r;
155 }
156 
157 int
158 VOP_CLOSE(struct vnode *vp, int fflag, struct ucred *cred, struct proc *p)
159 {
160 	int r;
161 	struct vop_close_args a;
162 	a.a_vp = vp;
163 	a.a_fflag = fflag;
164 	a.a_cred = cred;
165 	a.a_p = p;
166 
167 	ASSERT_VP_ISLOCKED(vp);
168 
169 	if (vp->v_op->vop_close == NULL)
170 		return (EOPNOTSUPP);
171 
172 	vp->v_inflight++;
173 	r = (vp->v_op->vop_close)(&a);
174 	vp->v_inflight--;
175 	return r;
176 }
177 
178 int
179 VOP_ACCESS(struct vnode *vp, int mode, struct ucred *cred, struct proc *p)
180 {
181 	struct vop_access_args a;
182 	a.a_vp = vp;
183 	a.a_mode = mode;
184 	a.a_cred = cred;
185 	a.a_p = p;
186 
187 	ASSERT_VP_ISLOCKED(vp);
188 
189 	if (vp->v_op->vop_access == NULL)
190 		return (EOPNOTSUPP);
191 
192 	return ((vp->v_op->vop_access)(&a));
193 }
194 
195 int
196 VOP_GETATTR(struct vnode *vp, struct vattr *vap, struct ucred *cred,
197     struct proc *p)
198 {
199 	struct vop_getattr_args a;
200 	a.a_vp = vp;
201 	a.a_vap = vap;
202 	a.a_cred = cred;
203 	a.a_p = p;
204 
205 	if (vp->v_op->vop_getattr == NULL)
206 		return (EOPNOTSUPP);
207 
208 	return ((vp->v_op->vop_getattr)(&a));
209 }
210 
211 int
212 VOP_SETATTR(struct vnode *vp, struct vattr *vap, struct ucred *cred,
213     struct proc *p)
214 {
215 	int r;
216 	struct vop_setattr_args a;
217 	a.a_vp = vp;
218 	a.a_vap = vap;
219 	a.a_cred = cred;
220 	a.a_p = p;
221 
222 	ASSERT_VP_ISLOCKED(vp);
223 
224 	if (vp->v_op->vop_setattr == NULL)
225 		return (EOPNOTSUPP);
226 
227 	vp->v_inflight++;
228 	r = (vp->v_op->vop_setattr)(&a);
229 	vp->v_inflight--;
230 	return r;
231 }
232 
233 int
234 VOP_READ(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred)
235 {
236 	struct vop_read_args a;
237 	a.a_vp = vp;
238 	a.a_uio = uio;
239 	a.a_ioflag = ioflag;
240 	a.a_cred = cred;
241 
242 	ASSERT_VP_ISLOCKED(vp);
243 
244 	if (vp->v_op->vop_read == NULL)
245 		return (EOPNOTSUPP);
246 
247 	return ((vp->v_op->vop_read)(&a));
248 }
249 
250 int
251 VOP_WRITE(struct vnode *vp, struct uio *uio, int ioflag,
252     struct ucred *cred)
253 {
254 	int r;
255 	struct vop_write_args a;
256 	a.a_vp = vp;
257 	a.a_uio = uio;
258 	a.a_ioflag = ioflag;
259 	a.a_cred = cred;
260 
261 	ASSERT_VP_ISLOCKED(vp);
262 
263 	if (vp->v_op->vop_write == NULL)
264 		return (EOPNOTSUPP);
265 
266 	vp->v_inflight++;
267 	r = (vp->v_op->vop_write)(&a);
268 	vp->v_inflight--;
269 	return r;
270 }
271 
272 int
273 VOP_IOCTL(struct vnode *vp, u_long command, void *data, int fflag,
274     struct ucred *cred, struct proc *p)
275 {
276 	int r;
277 	struct vop_ioctl_args a;
278 	a.a_vp = vp;
279 	a.a_command = command;
280 	a.a_data = data;
281 	a.a_fflag = fflag;
282 	a.a_cred = cred;
283 	a.a_p = p;
284 
285 	if (vp->v_op->vop_ioctl == NULL)
286 		return (EOPNOTSUPP);
287 
288 	vp->v_inflight++;
289 	r = (vp->v_op->vop_ioctl)(&a);
290 	vp->v_inflight--;
291 	return r;
292 }
293 
294 int
295 VOP_POLL(struct vnode *vp, int fflag, int events, struct proc *p)
296 {
297 	struct vop_poll_args a;
298 	a.a_vp = vp;
299 	a.a_fflag = fflag;
300 	a.a_events = events;
301 	a.a_p = p;
302 
303 	if (vp->v_op->vop_poll == NULL)
304 		return (EOPNOTSUPP);
305 
306 	return ((vp->v_op->vop_poll)(&a));
307 }
308 
309 int
310 VOP_KQFILTER(struct vnode *vp, int fflag, struct knote *kn)
311 {
312 	struct vop_kqfilter_args a;
313 	a.a_vp = vp;
314 	a.a_fflag = fflag;
315 	a.a_kn = kn;
316 
317 	if (vp->v_op->vop_kqfilter == NULL)
318 		return (EOPNOTSUPP);
319 
320 	return ((vp->v_op->vop_kqfilter)(&a));
321 }
322 
323 int
324 VOP_REVOKE(struct vnode *vp, int flags)
325 {
326 	struct vop_revoke_args a;
327 	a.a_vp = vp;
328 	a.a_flags = flags;
329 
330 	if (vp->v_op->vop_revoke == NULL)
331 		return (EOPNOTSUPP);
332 
333 	return ((vp->v_op->vop_revoke)(&a));
334 }
335 
336 int
337 VOP_FSYNC(struct vnode *vp, struct ucred *cred, int waitfor,
338     struct proc *p)
339 {
340 	int r, s;
341 	struct vop_fsync_args a;
342 	a.a_vp = vp;
343 	a.a_cred = cred;
344 	a.a_waitfor = waitfor;
345 	a.a_p = p;
346 
347 	ASSERT_VP_ISLOCKED(vp);
348 
349 	if (vp->v_op->vop_fsync == NULL)
350 		return (EOPNOTSUPP);
351 
352 	vp->v_inflight++;
353 	r = (vp->v_op->vop_fsync)(&a);
354 	vp->v_inflight--;
355 	s = splbio();
356 	if (r == 0 && vp->v_bioflag & VBIOERROR)
357 		r = EIO;
358 	splx(s);
359 	return r;
360 }
361 
362 int
363 VOP_REMOVE(struct vnode *dvp, struct vnode *vp, struct componentname *cnp)
364 {
365 	int r;
366 	struct vop_remove_args a;
367 	a.a_dvp = dvp;
368         a.a_vp = vp;
369 	a.a_cnp = cnp;
370 
371 	ASSERT_VP_ISLOCKED(dvp);
372 	ASSERT_VP_ISLOCKED(vp);
373 
374 	if (dvp->v_op->vop_remove == NULL)
375 		return (EOPNOTSUPP);
376 
377 	dvp->v_inflight++;
378 	r = (dvp->v_op->vop_remove)(&a);
379 	dvp->v_inflight--;
380 	return r;
381 }
382 
383 int
384 VOP_LINK(struct vnode *dvp, struct vnode *vp, struct componentname *cnp)
385 {
386 	int r;
387 	struct vop_link_args a;
388 	a.a_dvp = dvp;
389 	a.a_vp = vp;
390 	a.a_cnp = cnp;
391 
392 	ASSERT_VP_ISLOCKED(dvp);
393 
394 	if (dvp->v_op->vop_link == NULL)
395 		return (EOPNOTSUPP);
396 
397 	dvp->v_inflight++;
398 	vp->v_inflight++;
399 	r = (dvp->v_op->vop_link)(&a);
400 	dvp->v_inflight--;
401 	vp->v_inflight--;
402 	return r;
403 }
404 
405 int
406 VOP_RENAME(struct vnode *fdvp, struct vnode *fvp,
407     struct componentname *fcnp, struct vnode *tdvp, struct vnode *tvp,
408     struct componentname *tcnp)
409 {
410 	int r;
411 	struct vop_rename_args a;
412 	a.a_fdvp = fdvp;
413 	a.a_fvp = fvp;
414 	a.a_fcnp = fcnp;
415 	a.a_tdvp = tdvp;
416 	a.a_tvp = tvp;
417 	a.a_tcnp = tcnp;
418 
419 	ASSERT_VP_ISLOCKED(tdvp);
420 
421 	if (fdvp->v_op->vop_rename == NULL)
422 		return (EOPNOTSUPP);
423 
424 	fdvp->v_inflight++;
425 	tdvp->v_inflight++;
426 	r = (fdvp->v_op->vop_rename)(&a);
427 	fdvp->v_inflight--;
428 	tdvp->v_inflight--;
429 	return r;
430 }
431 
432 int
433 VOP_MKDIR(struct vnode *dvp, struct vnode **vpp,
434     struct componentname *cnp, struct vattr *vap)
435 {
436 	int r;
437 	struct vop_mkdir_args a;
438 	a.a_dvp = dvp;
439 	a.a_vpp = vpp;
440 	a.a_cnp = cnp;
441 	a.a_vap = vap;
442 
443 	ASSERT_VP_ISLOCKED(dvp);
444 
445 	if (dvp->v_op->vop_mkdir == NULL)
446 		return (EOPNOTSUPP);
447 
448 	dvp->v_inflight++;
449 	r = (dvp->v_op->vop_mkdir)(&a);
450 	dvp->v_inflight--;
451 	return r;
452 }
453 
454 int
455 VOP_RMDIR(struct vnode *dvp, struct vnode *vp, struct componentname *cnp)
456 {
457 	int r;
458 	struct vop_rmdir_args a;
459 	a.a_dvp = dvp;
460 	a.a_vp = vp;
461 	a.a_cnp = cnp;
462 
463 	ASSERT_VP_ISLOCKED(dvp);
464 	ASSERT_VP_ISLOCKED(vp);
465 
466 	KASSERT(dvp != vp);
467 
468 	if (dvp->v_op->vop_rmdir == NULL)
469 		return (EOPNOTSUPP);
470 
471 	dvp->v_inflight++;
472 	vp->v_inflight++;
473 	r = (dvp->v_op->vop_rmdir)(&a);
474 	dvp->v_inflight--;
475 	vp->v_inflight--;
476 	return r;
477 }
478 
479 int
480 VOP_SYMLINK(struct vnode *dvp, struct vnode **vpp,
481     struct componentname *cnp, struct vattr *vap, char *target)
482 {
483 	int r;
484 	struct vop_symlink_args a;
485 	a.a_dvp = dvp;
486 	a.a_vpp = vpp;
487 	a.a_cnp = cnp;
488 	a.a_vap = vap;
489 	a.a_target = target;
490 
491 	ASSERT_VP_ISLOCKED(dvp);
492 
493 	if (dvp->v_op->vop_symlink == NULL)
494 		return (EOPNOTSUPP);
495 
496 	dvp->v_inflight++;
497 	r = (dvp->v_op->vop_symlink)(&a);
498 	dvp->v_inflight--;
499 	return r;
500 }
501 
502 int
503 VOP_READDIR(struct vnode *vp, struct uio *uio, struct ucred *cred,
504     int *eofflag)
505 {
506 	int r;
507 	struct vop_readdir_args a;
508 	a.a_vp = vp;
509 	a.a_uio = uio;
510 	a.a_cred = cred;
511 	a.a_eofflag = eofflag;
512 
513 	ASSERT_VP_ISLOCKED(vp);
514 
515 	if (vp->v_op->vop_readdir == NULL)
516 		return (EOPNOTSUPP);
517 
518 	vp->v_inflight++;
519 	r = (vp->v_op->vop_readdir)(&a);
520 	vp->v_inflight--;
521 	return r;
522 }
523 
524 int
525 VOP_READLINK(struct vnode *vp, struct uio *uio, struct ucred *cred)
526 {
527 	int r;
528 	struct vop_readlink_args a;
529 	a.a_vp = vp;
530 	a.a_uio = uio;
531 	a.a_cred = cred;
532 
533 	ASSERT_VP_ISLOCKED(vp);
534 
535 	if (vp->v_op->vop_readlink == NULL)
536 		return (EOPNOTSUPP);
537 
538 	vp->v_inflight++;
539 	r = (vp->v_op->vop_readlink)(&a);
540 	vp->v_inflight--;
541 	return r;
542 }
543 
544 int
545 VOP_ABORTOP(struct vnode *dvp, struct componentname *cnp)
546 {
547 	int r;
548 	struct vop_abortop_args a;
549 	a.a_dvp = dvp;
550 	a.a_cnp = cnp;
551 
552 	if (dvp->v_op->vop_abortop == NULL)
553 		return (EOPNOTSUPP);
554 
555 	dvp->v_inflight++;
556 	r = (dvp->v_op->vop_abortop)(&a);
557 	dvp->v_inflight--;
558 	return r;
559 }
560 
561 int
562 VOP_INACTIVE(struct vnode *vp, struct proc *p)
563 {
564 	struct vop_inactive_args a;
565 	a.a_vp = vp;
566 	a.a_p = p;
567 
568 	ASSERT_VP_ISLOCKED(vp);
569 
570 	if (vp->v_op->vop_inactive == NULL)
571 		return (EOPNOTSUPP);
572 
573 	return ((vp->v_op->vop_inactive)(&a));
574 }
575 
576 int
577 VOP_RECLAIM(struct vnode *vp, struct proc *p)
578 {
579 	int r;
580 	struct vop_reclaim_args a;
581 	a.a_vp = vp;
582 	a.a_p = p;
583 
584 	if (vp->v_op->vop_reclaim == NULL)
585 		return (EOPNOTSUPP);
586 
587 	vp->v_inflight++;
588 	r = (vp->v_op->vop_reclaim)(&a);
589 	vp->v_inflight--;
590 	return r;
591 }
592 
593 int
594 VOP_LOCK(struct vnode *vp, int flags)
595 {
596 	struct vop_lock_args a;
597 	a.a_vp = vp;
598 	a.a_flags = flags;
599 
600 	if (vp->v_op->vop_lock == NULL)
601 		return (EOPNOTSUPP);
602 
603 	return ((vp->v_op->vop_lock)(&a));
604 }
605 
606 int
607 VOP_UNLOCK(struct vnode *vp)
608 {
609 	struct vop_unlock_args a;
610 	a.a_vp = vp;
611 
612 	if (vp->v_op->vop_unlock == NULL)
613 		return (EOPNOTSUPP);
614 
615 	return ((vp->v_op->vop_unlock)(&a));
616 }
617 
618 int
619 VOP_BMAP(struct vnode *vp, daddr_t bn, struct vnode **vpp,
620     daddr_t *bnp, int *runp)
621 {
622 	struct vop_bmap_args a;
623 	a.a_vp = vp;
624 	a.a_bn = bn;
625 	a.a_vpp = vpp;
626 	a.a_bnp = bnp;
627 	a.a_runp = runp;
628 
629 	ASSERT_VP_ISLOCKED(vp);
630 
631 	if (vp->v_op->vop_bmap == NULL)
632 		return (EOPNOTSUPP);
633 
634 	return ((vp->v_op->vop_bmap)(&a));
635 }
636 
637 int
638 VOP_PRINT(struct vnode *vp)
639 {
640 	struct vop_print_args a;
641 	a.a_vp = vp;
642 
643 	if (vp->v_op->vop_print == NULL)
644 		return (EOPNOTSUPP);
645 
646 	return ((vp->v_op->vop_print)(&a));
647 }
648 
649 int
650 VOP_PATHCONF(struct vnode *vp, int name, register_t *retval)
651 {
652 	struct vop_pathconf_args a;
653 
654 	/*
655 	 * Handle names that are constant across filesystem
656 	 */
657 	switch (name) {
658 	case _PC_PATH_MAX:
659 		*retval = PATH_MAX;
660 		return (0);
661 	case _PC_PIPE_BUF:
662 		*retval = PIPE_BUF;
663 		return (0);
664 	case _PC_ASYNC_IO:
665 	case _PC_PRIO_IO:
666 	case _PC_SYNC_IO:
667 		*retval = 0;
668 		return (0);
669 
670 	}
671 
672 	a.a_vp = vp;
673 	a.a_name = name;
674 	a.a_retval = retval;
675 
676 	ASSERT_VP_ISLOCKED(vp);
677 
678 	if (vp->v_op->vop_pathconf == NULL)
679 		return (EOPNOTSUPP);
680 
681 	return ((vp->v_op->vop_pathconf)(&a));
682 }
683 
684 int
685 VOP_ADVLOCK(struct vnode *vp, void *id, int op, struct flock *fl, int flags)
686 {
687 	struct vop_advlock_args a;
688 	a.a_vp = vp;
689 	a.a_id = id;
690 	a.a_op = op;
691 	a.a_fl = fl;
692 	a.a_flags = flags;
693 
694 	if (vp->v_op->vop_advlock == NULL)
695 		return (EOPNOTSUPP);
696 
697 	return (vp->v_op->vop_advlock)(&a);
698 }
699 
700 int
701 VOP_STRATEGY(struct buf *bp)
702 {
703 	struct vop_strategy_args a;
704 	a.a_bp = bp;
705 
706 	if ((ISSET(bp->b_flags, B_BC)) && (!ISSET(bp->b_flags, B_DMA)))
707 		panic("Non dma reachable buffer passed to VOP_STRATEGY");
708 
709 	if (bp->b_vp->v_op->vop_strategy == NULL)
710 		return (EOPNOTSUPP);
711 
712 	return ((bp->b_vp->v_op->vop_strategy)(&a));
713 }
714 
715 int
716 VOP_BWRITE(struct buf *bp)
717 {
718 	struct vop_bwrite_args a;
719 	a.a_bp = bp;
720 
721 	if (bp->b_vp->v_op->vop_bwrite == NULL)
722 		return (EOPNOTSUPP);
723 
724 	return ((bp->b_vp->v_op->vop_bwrite)(&a));
725 }
726