xref: /titanic_44/usr/src/uts/common/fs/zfs/zfs_vnops.c (revision b9bc7f7832704fda46b4d6b04f3f7be1227dc644)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /* Portions Copyright 2007 Jeremy Teo */
27 
28 #pragma ident	"%Z%%M%	%I%	%E% SMI"
29 
30 #include <sys/types.h>
31 #include <sys/param.h>
32 #include <sys/time.h>
33 #include <sys/systm.h>
34 #include <sys/sysmacros.h>
35 #include <sys/resource.h>
36 #include <sys/vfs.h>
37 #include <sys/vfs_opreg.h>
38 #include <sys/vnode.h>
39 #include <sys/file.h>
40 #include <sys/stat.h>
41 #include <sys/kmem.h>
42 #include <sys/taskq.h>
43 #include <sys/uio.h>
44 #include <sys/vmsystm.h>
45 #include <sys/atomic.h>
46 #include <sys/vm.h>
47 #include <vm/seg_vn.h>
48 #include <vm/pvn.h>
49 #include <vm/as.h>
50 #include <sys/mman.h>
51 #include <sys/pathname.h>
52 #include <sys/cmn_err.h>
53 #include <sys/errno.h>
54 #include <sys/unistd.h>
55 #include <sys/zfs_dir.h>
56 #include <sys/zfs_acl.h>
57 #include <sys/zfs_ioctl.h>
58 #include <sys/fs/zfs.h>
59 #include <sys/dmu.h>
60 #include <sys/spa.h>
61 #include <sys/txg.h>
62 #include <sys/dbuf.h>
63 #include <sys/zap.h>
64 #include <sys/dirent.h>
65 #include <sys/policy.h>
66 #include <sys/sunddi.h>
67 #include <sys/filio.h>
68 #include "fs/fs_subr.h"
69 #include <sys/zfs_ctldir.h>
70 #include <sys/zfs_fuid.h>
71 #include <sys/dnlc.h>
72 #include <sys/zfs_rlock.h>
73 #include <sys/extdirent.h>
74 #include <sys/kidmap.h>
75 #include <sys/cred_impl.h>
76 
77 /*
78  * Programming rules.
79  *
80  * Each vnode op performs some logical unit of work.  To do this, the ZPL must
81  * properly lock its in-core state, create a DMU transaction, do the work,
82  * record this work in the intent log (ZIL), commit the DMU transaction,
83  * and wait for the intent log to commit if it is a synchronous operation.
84  * Moreover, the vnode ops must work in both normal and log replay context.
85  * The ordering of events is important to avoid deadlocks and references
86  * to freed memory.  The example below illustrates the following Big Rules:
87  *
88  *  (1) A check must be made in each zfs thread for a mounted file system.
89  *	This is done avoiding races using ZFS_ENTER(zfsvfs).
90  *      A ZFS_EXIT(zfsvfs) is needed before all returns.  Any znodes
91  *      must be checked with ZFS_VERIFY_ZP(zp).  Both of these macros
92  *      can return EIO from the calling function.
93  *
94  *  (2)	VN_RELE() should always be the last thing except for zil_commit()
95  *	(if necessary) and ZFS_EXIT(). This is for 3 reasons:
96  *	First, if it's the last reference, the vnode/znode
97  *	can be freed, so the zp may point to freed memory.  Second, the last
98  *	reference will call zfs_zinactive(), which may induce a lot of work --
99  *	pushing cached pages (which acquires range locks) and syncing out
100  *	cached atime changes.  Third, zfs_zinactive() may require a new tx,
101  *	which could deadlock the system if you were already holding one.
102  *
103  *  (3)	All range locks must be grabbed before calling dmu_tx_assign(),
104  *	as they can span dmu_tx_assign() calls.
105  *
106  *  (4)	Always pass zfsvfs->z_assign as the second argument to dmu_tx_assign().
107  *	In normal operation, this will be TXG_NOWAIT.  During ZIL replay,
108  *	it will be a specific txg.  Either way, dmu_tx_assign() never blocks.
109  *	This is critical because we don't want to block while holding locks.
110  *	Note, in particular, that if a lock is sometimes acquired before
111  *	the tx assigns, and sometimes after (e.g. z_lock), then failing to
112  *	use a non-blocking assign can deadlock the system.  The scenario:
113  *
114  *	Thread A has grabbed a lock before calling dmu_tx_assign().
115  *	Thread B is in an already-assigned tx, and blocks for this lock.
116  *	Thread A calls dmu_tx_assign(TXG_WAIT) and blocks in txg_wait_open()
117  *	forever, because the previous txg can't quiesce until B's tx commits.
118  *
119  *	If dmu_tx_assign() returns ERESTART and zfsvfs->z_assign is TXG_NOWAIT,
120  *	then drop all locks, call dmu_tx_wait(), and try again.
121  *
122  *  (5)	If the operation succeeded, generate the intent log entry for it
123  *	before dropping locks.  This ensures that the ordering of events
124  *	in the intent log matches the order in which they actually occurred.
125  *
126  *  (6)	At the end of each vnode op, the DMU tx must always commit,
127  *	regardless of whether there were any errors.
128  *
129  *  (7)	After dropping all locks, invoke zil_commit(zilog, seq, foid)
130  *	to ensure that synchronous semantics are provided when necessary.
131  *
132  * In general, this is how things should be ordered in each vnode op:
133  *
134  *	ZFS_ENTER(zfsvfs);		// exit if unmounted
135  * top:
136  *	zfs_dirent_lock(&dl, ...)	// lock directory entry (may VN_HOLD())
137  *	rw_enter(...);			// grab any other locks you need
138  *	tx = dmu_tx_create(...);	// get DMU tx
139  *	dmu_tx_hold_*();		// hold each object you might modify
140  *	error = dmu_tx_assign(tx, zfsvfs->z_assign);	// try to assign
141  *	if (error) {
142  *		rw_exit(...);		// drop locks
143  *		zfs_dirent_unlock(dl);	// unlock directory entry
144  *		VN_RELE(...);		// release held vnodes
145  *		if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) {
146  *			dmu_tx_wait(tx);
147  *			dmu_tx_abort(tx);
148  *			goto top;
149  *		}
150  *		dmu_tx_abort(tx);	// abort DMU tx
151  *		ZFS_EXIT(zfsvfs);	// finished in zfs
152  *		return (error);		// really out of space
153  *	}
154  *	error = do_real_work();		// do whatever this VOP does
155  *	if (error == 0)
156  *		zfs_log_*(...);		// on success, make ZIL entry
157  *	dmu_tx_commit(tx);		// commit DMU tx -- error or not
158  *	rw_exit(...);			// drop locks
159  *	zfs_dirent_unlock(dl);		// unlock directory entry
160  *	VN_RELE(...);			// release held vnodes
161  *	zil_commit(zilog, seq, foid);	// synchronous when necessary
162  *	ZFS_EXIT(zfsvfs);		// finished in zfs
163  *	return (error);			// done, report error
164  */
165 
166 /* ARGSUSED */
167 static int
168 zfs_open(vnode_t **vpp, int flag, cred_t *cr, caller_context_t *ct)
169 {
170 	znode_t	*zp = VTOZ(*vpp);
171 
172 	if ((flag & FWRITE) && (zp->z_phys->zp_flags & ZFS_APPENDONLY) &&
173 	    ((flag & FAPPEND) == 0)) {
174 		return (EPERM);
175 	}
176 
177 	if (!zfs_has_ctldir(zp) && zp->z_zfsvfs->z_vscan &&
178 	    ZTOV(zp)->v_type == VREG &&
179 	    !(zp->z_phys->zp_flags & ZFS_AV_QUARANTINED) &&
180 	    zp->z_phys->zp_size > 0)
181 		if (fs_vscan(*vpp, cr, 0) != 0)
182 			return (EACCES);
183 
184 	/* Keep a count of the synchronous opens in the znode */
185 	if (flag & (FSYNC | FDSYNC))
186 		atomic_inc_32(&zp->z_sync_cnt);
187 
188 	return (0);
189 }
190 
191 /* ARGSUSED */
192 static int
193 zfs_close(vnode_t *vp, int flag, int count, offset_t offset, cred_t *cr,
194     caller_context_t *ct)
195 {
196 	znode_t	*zp = VTOZ(vp);
197 
198 	/* Decrement the synchronous opens in the znode */
199 	if ((flag & (FSYNC | FDSYNC)) && (count == 1))
200 		atomic_dec_32(&zp->z_sync_cnt);
201 
202 	/*
203 	 * Clean up any locks held by this process on the vp.
204 	 */
205 	cleanlocks(vp, ddi_get_pid(), 0);
206 	cleanshares(vp, ddi_get_pid());
207 
208 	if (!zfs_has_ctldir(zp) && zp->z_zfsvfs->z_vscan &&
209 	    ZTOV(zp)->v_type == VREG &&
210 	    !(zp->z_phys->zp_flags & ZFS_AV_QUARANTINED) &&
211 	    zp->z_phys->zp_size > 0)
212 		VERIFY(fs_vscan(vp, cr, 1) == 0);
213 
214 	return (0);
215 }
216 
217 /*
218  * Lseek support for finding holes (cmd == _FIO_SEEK_HOLE) and
219  * data (cmd == _FIO_SEEK_DATA). "off" is an in/out parameter.
220  */
221 static int
222 zfs_holey(vnode_t *vp, int cmd, offset_t *off)
223 {
224 	znode_t	*zp = VTOZ(vp);
225 	uint64_t noff = (uint64_t)*off; /* new offset */
226 	uint64_t file_sz;
227 	int error;
228 	boolean_t hole;
229 
230 	file_sz = zp->z_phys->zp_size;
231 	if (noff >= file_sz)  {
232 		return (ENXIO);
233 	}
234 
235 	if (cmd == _FIO_SEEK_HOLE)
236 		hole = B_TRUE;
237 	else
238 		hole = B_FALSE;
239 
240 	error = dmu_offset_next(zp->z_zfsvfs->z_os, zp->z_id, hole, &noff);
241 
242 	/* end of file? */
243 	if ((error == ESRCH) || (noff > file_sz)) {
244 		/*
245 		 * Handle the virtual hole at the end of file.
246 		 */
247 		if (hole) {
248 			*off = file_sz;
249 			return (0);
250 		}
251 		return (ENXIO);
252 	}
253 
254 	if (noff < *off)
255 		return (error);
256 	*off = noff;
257 	return (error);
258 }
259 
260 /* ARGSUSED */
261 static int
262 zfs_ioctl(vnode_t *vp, int com, intptr_t data, int flag, cred_t *cred,
263     int *rvalp, caller_context_t *ct)
264 {
265 	offset_t off;
266 	int error;
267 	zfsvfs_t *zfsvfs;
268 	znode_t *zp;
269 
270 	switch (com) {
271 	case _FIOFFS:
272 		return (zfs_sync(vp->v_vfsp, 0, cred));
273 
274 		/*
275 		 * The following two ioctls are used by bfu.  Faking out,
276 		 * necessary to avoid bfu errors.
277 		 */
278 	case _FIOGDIO:
279 	case _FIOSDIO:
280 		return (0);
281 
282 	case _FIO_SEEK_DATA:
283 	case _FIO_SEEK_HOLE:
284 		if (ddi_copyin((void *)data, &off, sizeof (off), flag))
285 			return (EFAULT);
286 
287 		zp = VTOZ(vp);
288 		zfsvfs = zp->z_zfsvfs;
289 		ZFS_ENTER(zfsvfs);
290 		ZFS_VERIFY_ZP(zp);
291 
292 		/* offset parameter is in/out */
293 		error = zfs_holey(vp, com, &off);
294 		ZFS_EXIT(zfsvfs);
295 		if (error)
296 			return (error);
297 		if (ddi_copyout(&off, (void *)data, sizeof (off), flag))
298 			return (EFAULT);
299 		return (0);
300 	}
301 	return (ENOTTY);
302 }
303 
304 /*
305  * When a file is memory mapped, we must keep the IO data synchronized
306  * between the DMU cache and the memory mapped pages.  What this means:
307  *
308  * On Write:	If we find a memory mapped page, we write to *both*
309  *		the page and the dmu buffer.
310  *
311  * NOTE: We will always "break up" the IO into PAGESIZE uiomoves when
312  *	the file is memory mapped.
313  */
314 static int
315 mappedwrite(vnode_t *vp, int nbytes, uio_t *uio, dmu_tx_t *tx)
316 {
317 	znode_t	*zp = VTOZ(vp);
318 	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
319 	int64_t	start, off;
320 	int len = nbytes;
321 	int error = 0;
322 
323 	start = uio->uio_loffset;
324 	off = start & PAGEOFFSET;
325 	for (start &= PAGEMASK; len > 0; start += PAGESIZE) {
326 		page_t *pp;
327 		uint64_t bytes = MIN(PAGESIZE - off, len);
328 		uint64_t woff = uio->uio_loffset;
329 
330 		/*
331 		 * We don't want a new page to "appear" in the middle of
332 		 * the file update (because it may not get the write
333 		 * update data), so we grab a lock to block
334 		 * zfs_getpage().
335 		 */
336 		rw_enter(&zp->z_map_lock, RW_WRITER);
337 		if (pp = page_lookup(vp, start, SE_SHARED)) {
338 			caddr_t va;
339 
340 			rw_exit(&zp->z_map_lock);
341 			va = ppmapin(pp, PROT_READ | PROT_WRITE, (caddr_t)-1L);
342 			error = uiomove(va+off, bytes, UIO_WRITE, uio);
343 			if (error == 0) {
344 				dmu_write(zfsvfs->z_os, zp->z_id,
345 				    woff, bytes, va+off, tx);
346 			}
347 			ppmapout(va);
348 			page_unlock(pp);
349 		} else {
350 			error = dmu_write_uio(zfsvfs->z_os, zp->z_id,
351 			    uio, bytes, tx);
352 			rw_exit(&zp->z_map_lock);
353 		}
354 		len -= bytes;
355 		off = 0;
356 		if (error)
357 			break;
358 	}
359 	return (error);
360 }
361 
362 /*
363  * When a file is memory mapped, we must keep the IO data synchronized
364  * between the DMU cache and the memory mapped pages.  What this means:
365  *
366  * On Read:	We "read" preferentially from memory mapped pages,
367  *		else we default from the dmu buffer.
368  *
369  * NOTE: We will always "break up" the IO into PAGESIZE uiomoves when
370  *	the file is memory mapped.
371  */
372 static int
373 mappedread(vnode_t *vp, int nbytes, uio_t *uio)
374 {
375 	znode_t *zp = VTOZ(vp);
376 	objset_t *os = zp->z_zfsvfs->z_os;
377 	int64_t	start, off;
378 	int len = nbytes;
379 	int error = 0;
380 
381 	start = uio->uio_loffset;
382 	off = start & PAGEOFFSET;
383 	for (start &= PAGEMASK; len > 0; start += PAGESIZE) {
384 		page_t *pp;
385 		uint64_t bytes = MIN(PAGESIZE - off, len);
386 
387 		if (pp = page_lookup(vp, start, SE_SHARED)) {
388 			caddr_t va;
389 
390 			va = ppmapin(pp, PROT_READ, (caddr_t)-1L);
391 			error = uiomove(va + off, bytes, UIO_READ, uio);
392 			ppmapout(va);
393 			page_unlock(pp);
394 		} else {
395 			error = dmu_read_uio(os, zp->z_id, uio, bytes);
396 		}
397 		len -= bytes;
398 		off = 0;
399 		if (error)
400 			break;
401 	}
402 	return (error);
403 }
404 
405 offset_t zfs_read_chunk_size = 1024 * 1024; /* Tunable */
406 
407 /*
408  * Read bytes from specified file into supplied buffer.
409  *
410  *	IN:	vp	- vnode of file to be read from.
411  *		uio	- structure supplying read location, range info,
412  *			  and return buffer.
413  *		ioflag	- SYNC flags; used to provide FRSYNC semantics.
414  *		cr	- credentials of caller.
415  *		ct	- caller context
416  *
417  *	OUT:	uio	- updated offset and range, buffer filled.
418  *
419  *	RETURN:	0 if success
420  *		error code if failure
421  *
422  * Side Effects:
423  *	vp - atime updated if byte count > 0
424  */
425 /* ARGSUSED */
426 static int
427 zfs_read(vnode_t *vp, uio_t *uio, int ioflag, cred_t *cr, caller_context_t *ct)
428 {
429 	znode_t		*zp = VTOZ(vp);
430 	zfsvfs_t	*zfsvfs = zp->z_zfsvfs;
431 	objset_t	*os;
432 	ssize_t		n, nbytes;
433 	int		error;
434 	rl_t		*rl;
435 
436 	ZFS_ENTER(zfsvfs);
437 	ZFS_VERIFY_ZP(zp);
438 	os = zfsvfs->z_os;
439 
440 	/*
441 	 * Validate file offset
442 	 */
443 	if (uio->uio_loffset < (offset_t)0) {
444 		ZFS_EXIT(zfsvfs);
445 		return (EINVAL);
446 	}
447 
448 	/*
449 	 * Fasttrack empty reads
450 	 */
451 	if (uio->uio_resid == 0) {
452 		ZFS_EXIT(zfsvfs);
453 		return (0);
454 	}
455 
456 	/*
457 	 * Check for mandatory locks
458 	 */
459 	if (MANDMODE((mode_t)zp->z_phys->zp_mode)) {
460 		if (error = chklock(vp, FREAD,
461 		    uio->uio_loffset, uio->uio_resid, uio->uio_fmode, ct)) {
462 			ZFS_EXIT(zfsvfs);
463 			return (error);
464 		}
465 	}
466 
467 	/*
468 	 * If we're in FRSYNC mode, sync out this znode before reading it.
469 	 */
470 	if (ioflag & FRSYNC)
471 		zil_commit(zfsvfs->z_log, zp->z_last_itx, zp->z_id);
472 
473 	/*
474 	 * Lock the range against changes.
475 	 */
476 	rl = zfs_range_lock(zp, uio->uio_loffset, uio->uio_resid, RL_READER);
477 
478 	/*
479 	 * If we are reading past end-of-file we can skip
480 	 * to the end; but we might still need to set atime.
481 	 */
482 	if (uio->uio_loffset >= zp->z_phys->zp_size) {
483 		error = 0;
484 		goto out;
485 	}
486 
487 	ASSERT(uio->uio_loffset < zp->z_phys->zp_size);
488 	n = MIN(uio->uio_resid, zp->z_phys->zp_size - uio->uio_loffset);
489 
490 	while (n > 0) {
491 		nbytes = MIN(n, zfs_read_chunk_size -
492 		    P2PHASE(uio->uio_loffset, zfs_read_chunk_size));
493 
494 		if (vn_has_cached_data(vp))
495 			error = mappedread(vp, nbytes, uio);
496 		else
497 			error = dmu_read_uio(os, zp->z_id, uio, nbytes);
498 		if (error)
499 			break;
500 
501 		n -= nbytes;
502 	}
503 
504 out:
505 	zfs_range_unlock(rl);
506 
507 	ZFS_ACCESSTIME_STAMP(zfsvfs, zp);
508 	ZFS_EXIT(zfsvfs);
509 	return (error);
510 }
511 
512 /*
513  * Fault in the pages of the first n bytes specified by the uio structure.
514  * 1 byte in each page is touched and the uio struct is unmodified.
515  * Any error will exit this routine as this is only a best
516  * attempt to get the pages resident. This is a copy of ufs_trans_touch().
517  */
518 static void
519 zfs_prefault_write(ssize_t n, struct uio *uio)
520 {
521 	struct iovec *iov;
522 	ulong_t cnt, incr;
523 	caddr_t p;
524 	uint8_t tmp;
525 
526 	iov = uio->uio_iov;
527 
528 	while (n) {
529 		cnt = MIN(iov->iov_len, n);
530 		if (cnt == 0) {
531 			/* empty iov entry */
532 			iov++;
533 			continue;
534 		}
535 		n -= cnt;
536 		/*
537 		 * touch each page in this segment.
538 		 */
539 		p = iov->iov_base;
540 		while (cnt) {
541 			switch (uio->uio_segflg) {
542 			case UIO_USERSPACE:
543 			case UIO_USERISPACE:
544 				if (fuword8(p, &tmp))
545 					return;
546 				break;
547 			case UIO_SYSSPACE:
548 				if (kcopy(p, &tmp, 1))
549 					return;
550 				break;
551 			}
552 			incr = MIN(cnt, PAGESIZE);
553 			p += incr;
554 			cnt -= incr;
555 		}
556 		/*
557 		 * touch the last byte in case it straddles a page.
558 		 */
559 		p--;
560 		switch (uio->uio_segflg) {
561 		case UIO_USERSPACE:
562 		case UIO_USERISPACE:
563 			if (fuword8(p, &tmp))
564 				return;
565 			break;
566 		case UIO_SYSSPACE:
567 			if (kcopy(p, &tmp, 1))
568 				return;
569 			break;
570 		}
571 		iov++;
572 	}
573 }
574 
575 /*
576  * Write the bytes to a file.
577  *
578  *	IN:	vp	- vnode of file to be written to.
579  *		uio	- structure supplying write location, range info,
580  *			  and data buffer.
581  *		ioflag	- FAPPEND flag set if in append mode.
582  *		cr	- credentials of caller.
583  *		ct	- caller context (NFS/CIFS fem monitor only)
584  *
585  *	OUT:	uio	- updated offset and range.
586  *
587  *	RETURN:	0 if success
588  *		error code if failure
589  *
590  * Timestamps:
591  *	vp - ctime|mtime updated if byte count > 0
592  */
593 /* ARGSUSED */
594 static int
595 zfs_write(vnode_t *vp, uio_t *uio, int ioflag, cred_t *cr, caller_context_t *ct)
596 {
597 	znode_t		*zp = VTOZ(vp);
598 	rlim64_t	limit = uio->uio_llimit;
599 	ssize_t		start_resid = uio->uio_resid;
600 	ssize_t		tx_bytes;
601 	uint64_t	end_size;
602 	dmu_tx_t	*tx;
603 	zfsvfs_t	*zfsvfs = zp->z_zfsvfs;
604 	zilog_t		*zilog;
605 	offset_t	woff;
606 	ssize_t		n, nbytes;
607 	rl_t		*rl;
608 	int		max_blksz = zfsvfs->z_max_blksz;
609 	uint64_t	pflags = zp->z_phys->zp_flags;
610 	int		error;
611 
612 	/*
613 	 * If immutable or not appending then return EPERM
614 	 */
615 	if ((pflags & (ZFS_IMMUTABLE | ZFS_READONLY)) ||
616 	    ((pflags & ZFS_APPENDONLY) && !(ioflag & FAPPEND) &&
617 	    (uio->uio_loffset < zp->z_phys->zp_size)))
618 		return (EPERM);
619 
620 	/*
621 	 * Fasttrack empty write
622 	 */
623 	n = start_resid;
624 	if (n == 0)
625 		return (0);
626 
627 	if (limit == RLIM64_INFINITY || limit > MAXOFFSET_T)
628 		limit = MAXOFFSET_T;
629 
630 	ZFS_ENTER(zfsvfs);
631 	ZFS_VERIFY_ZP(zp);
632 	zilog = zfsvfs->z_log;
633 
634 	/*
635 	 * Pre-fault the pages to ensure slow (eg NFS) pages
636 	 * don't hold up txg.
637 	 */
638 	zfs_prefault_write(n, uio);
639 
640 	/*
641 	 * If in append mode, set the io offset pointer to eof.
642 	 */
643 	if (ioflag & FAPPEND) {
644 		/*
645 		 * Range lock for a file append:
646 		 * The value for the start of range will be determined by
647 		 * zfs_range_lock() (to guarantee append semantics).
648 		 * If this write will cause the block size to increase,
649 		 * zfs_range_lock() will lock the entire file, so we must
650 		 * later reduce the range after we grow the block size.
651 		 */
652 		rl = zfs_range_lock(zp, 0, n, RL_APPEND);
653 		if (rl->r_len == UINT64_MAX) {
654 			/* overlocked, zp_size can't change */
655 			woff = uio->uio_loffset = zp->z_phys->zp_size;
656 		} else {
657 			woff = uio->uio_loffset = rl->r_off;
658 		}
659 	} else {
660 		woff = uio->uio_loffset;
661 		/*
662 		 * Validate file offset
663 		 */
664 		if (woff < 0) {
665 			ZFS_EXIT(zfsvfs);
666 			return (EINVAL);
667 		}
668 
669 		/*
670 		 * If we need to grow the block size then zfs_range_lock()
671 		 * will lock a wider range than we request here.
672 		 * Later after growing the block size we reduce the range.
673 		 */
674 		rl = zfs_range_lock(zp, woff, n, RL_WRITER);
675 	}
676 
677 	if (woff >= limit) {
678 		zfs_range_unlock(rl);
679 		ZFS_EXIT(zfsvfs);
680 		return (EFBIG);
681 	}
682 
683 	if ((woff + n) > limit || woff > (limit - n))
684 		n = limit - woff;
685 
686 	/*
687 	 * Check for mandatory locks
688 	 */
689 	if (MANDMODE((mode_t)zp->z_phys->zp_mode) &&
690 	    (error = chklock(vp, FWRITE, woff, n, uio->uio_fmode, ct)) != 0) {
691 		zfs_range_unlock(rl);
692 		ZFS_EXIT(zfsvfs);
693 		return (error);
694 	}
695 	end_size = MAX(zp->z_phys->zp_size, woff + n);
696 
697 	/*
698 	 * Write the file in reasonable size chunks.  Each chunk is written
699 	 * in a separate transaction; this keeps the intent log records small
700 	 * and allows us to do more fine-grained space accounting.
701 	 */
702 	while (n > 0) {
703 		/*
704 		 * Start a transaction.
705 		 */
706 		woff = uio->uio_loffset;
707 		tx = dmu_tx_create(zfsvfs->z_os);
708 		dmu_tx_hold_bonus(tx, zp->z_id);
709 		dmu_tx_hold_write(tx, zp->z_id, woff, MIN(n, max_blksz));
710 		error = dmu_tx_assign(tx, zfsvfs->z_assign);
711 		if (error) {
712 			if (error == ERESTART &&
713 			    zfsvfs->z_assign == TXG_NOWAIT) {
714 				dmu_tx_wait(tx);
715 				dmu_tx_abort(tx);
716 				continue;
717 			}
718 			dmu_tx_abort(tx);
719 			break;
720 		}
721 
722 		/*
723 		 * If zfs_range_lock() over-locked we grow the blocksize
724 		 * and then reduce the lock range.  This will only happen
725 		 * on the first iteration since zfs_range_reduce() will
726 		 * shrink down r_len to the appropriate size.
727 		 */
728 		if (rl->r_len == UINT64_MAX) {
729 			uint64_t new_blksz;
730 
731 			if (zp->z_blksz > max_blksz) {
732 				ASSERT(!ISP2(zp->z_blksz));
733 				new_blksz = MIN(end_size, SPA_MAXBLOCKSIZE);
734 			} else {
735 				new_blksz = MIN(end_size, max_blksz);
736 			}
737 			zfs_grow_blocksize(zp, new_blksz, tx);
738 			zfs_range_reduce(rl, woff, n);
739 		}
740 
741 		/*
742 		 * XXX - should we really limit each write to z_max_blksz?
743 		 * Perhaps we should use SPA_MAXBLOCKSIZE chunks?
744 		 */
745 		nbytes = MIN(n, max_blksz - P2PHASE(woff, max_blksz));
746 		rw_enter(&zp->z_map_lock, RW_READER);
747 
748 		tx_bytes = uio->uio_resid;
749 		if (vn_has_cached_data(vp)) {
750 			rw_exit(&zp->z_map_lock);
751 			error = mappedwrite(vp, nbytes, uio, tx);
752 		} else {
753 			error = dmu_write_uio(zfsvfs->z_os, zp->z_id,
754 			    uio, nbytes, tx);
755 			rw_exit(&zp->z_map_lock);
756 		}
757 		tx_bytes -= uio->uio_resid;
758 
759 		/*
760 		 * If we made no progress, we're done.  If we made even
761 		 * partial progress, update the znode and ZIL accordingly.
762 		 */
763 		if (tx_bytes == 0) {
764 			dmu_tx_commit(tx);
765 			ASSERT(error != 0);
766 			break;
767 		}
768 
769 		/*
770 		 * Clear Set-UID/Set-GID bits on successful write if not
771 		 * privileged and at least one of the excute bits is set.
772 		 *
773 		 * It would be nice to to this after all writes have
774 		 * been done, but that would still expose the ISUID/ISGID
775 		 * to another app after the partial write is committed.
776 		 *
777 		 * Note: we don't call zfs_fuid_map_id() here because
778 		 * user 0 is not an ephemeral uid.
779 		 */
780 		mutex_enter(&zp->z_acl_lock);
781 		if ((zp->z_phys->zp_mode & (S_IXUSR | (S_IXUSR >> 3) |
782 		    (S_IXUSR >> 6))) != 0 &&
783 		    (zp->z_phys->zp_mode & (S_ISUID | S_ISGID)) != 0 &&
784 		    secpolicy_vnode_setid_retain(cr,
785 		    (zp->z_phys->zp_mode & S_ISUID) != 0 &&
786 		    zp->z_phys->zp_uid == 0) != 0) {
787 			zp->z_phys->zp_mode &= ~(S_ISUID | S_ISGID);
788 		}
789 		mutex_exit(&zp->z_acl_lock);
790 
791 		/*
792 		 * Update time stamp.  NOTE: This marks the bonus buffer as
793 		 * dirty, so we don't have to do it again for zp_size.
794 		 */
795 		zfs_time_stamper(zp, CONTENT_MODIFIED, tx);
796 
797 		/*
798 		 * Update the file size (zp_size) if it has changed;
799 		 * account for possible concurrent updates.
800 		 */
801 		while ((end_size = zp->z_phys->zp_size) < uio->uio_loffset)
802 			(void) atomic_cas_64(&zp->z_phys->zp_size, end_size,
803 			    uio->uio_loffset);
804 		zfs_log_write(zilog, tx, TX_WRITE, zp, woff, tx_bytes, ioflag);
805 		dmu_tx_commit(tx);
806 
807 		if (error != 0)
808 			break;
809 		ASSERT(tx_bytes == nbytes);
810 		n -= nbytes;
811 	}
812 
813 	zfs_range_unlock(rl);
814 
815 	/*
816 	 * If we're in replay mode, or we made no progress, return error.
817 	 * Otherwise, it's at least a partial write, so it's successful.
818 	 */
819 	if (zfsvfs->z_assign >= TXG_INITIAL || uio->uio_resid == start_resid) {
820 		ZFS_EXIT(zfsvfs);
821 		return (error);
822 	}
823 
824 	if (ioflag & (FSYNC | FDSYNC))
825 		zil_commit(zilog, zp->z_last_itx, zp->z_id);
826 
827 	ZFS_EXIT(zfsvfs);
828 	return (0);
829 }
830 
831 void
832 zfs_get_done(dmu_buf_t *db, void *vzgd)
833 {
834 	zgd_t *zgd = (zgd_t *)vzgd;
835 	rl_t *rl = zgd->zgd_rl;
836 	vnode_t *vp = ZTOV(rl->r_zp);
837 
838 	dmu_buf_rele(db, vzgd);
839 	zfs_range_unlock(rl);
840 	VN_RELE(vp);
841 	zil_add_vdev(zgd->zgd_zilog, DVA_GET_VDEV(BP_IDENTITY(zgd->zgd_bp)));
842 	kmem_free(zgd, sizeof (zgd_t));
843 }
844 
845 /*
846  * Get data to generate a TX_WRITE intent log record.
847  */
848 int
849 zfs_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
850 {
851 	zfsvfs_t *zfsvfs = arg;
852 	objset_t *os = zfsvfs->z_os;
853 	znode_t *zp;
854 	uint64_t off = lr->lr_offset;
855 	dmu_buf_t *db;
856 	rl_t *rl;
857 	zgd_t *zgd;
858 	int dlen = lr->lr_length;		/* length of user data */
859 	int error = 0;
860 
861 	ASSERT(zio);
862 	ASSERT(dlen != 0);
863 
864 	/*
865 	 * Nothing to do if the file has been removed
866 	 */
867 	if (zfs_zget(zfsvfs, lr->lr_foid, &zp) != 0)
868 		return (ENOENT);
869 	if (zp->z_unlinked) {
870 		VN_RELE(ZTOV(zp));
871 		return (ENOENT);
872 	}
873 
874 	/*
875 	 * Write records come in two flavors: immediate and indirect.
876 	 * For small writes it's cheaper to store the data with the
877 	 * log record (immediate); for large writes it's cheaper to
878 	 * sync the data and get a pointer to it (indirect) so that
879 	 * we don't have to write the data twice.
880 	 */
881 	if (buf != NULL) { /* immediate write */
882 		rl = zfs_range_lock(zp, off, dlen, RL_READER);
883 		/* test for truncation needs to be done while range locked */
884 		if (off >= zp->z_phys->zp_size) {
885 			error = ENOENT;
886 			goto out;
887 		}
888 		VERIFY(0 == dmu_read(os, lr->lr_foid, off, dlen, buf));
889 	} else { /* indirect write */
890 		uint64_t boff; /* block starting offset */
891 
892 		/*
893 		 * Have to lock the whole block to ensure when it's
894 		 * written out and it's checksum is being calculated
895 		 * that no one can change the data. We need to re-check
896 		 * blocksize after we get the lock in case it's changed!
897 		 */
898 		for (;;) {
899 			if (ISP2(zp->z_blksz)) {
900 				boff = P2ALIGN_TYPED(off, zp->z_blksz,
901 				    uint64_t);
902 			} else {
903 				boff = 0;
904 			}
905 			dlen = zp->z_blksz;
906 			rl = zfs_range_lock(zp, boff, dlen, RL_READER);
907 			if (zp->z_blksz == dlen)
908 				break;
909 			zfs_range_unlock(rl);
910 		}
911 		/* test for truncation needs to be done while range locked */
912 		if (off >= zp->z_phys->zp_size) {
913 			error = ENOENT;
914 			goto out;
915 		}
916 		zgd = (zgd_t *)kmem_alloc(sizeof (zgd_t), KM_SLEEP);
917 		zgd->zgd_rl = rl;
918 		zgd->zgd_zilog = zfsvfs->z_log;
919 		zgd->zgd_bp = &lr->lr_blkptr;
920 		VERIFY(0 == dmu_buf_hold(os, lr->lr_foid, boff, zgd, &db));
921 		ASSERT(boff == db->db_offset);
922 		lr->lr_blkoff = off - boff;
923 		error = dmu_sync(zio, db, &lr->lr_blkptr,
924 		    lr->lr_common.lrc_txg, zfs_get_done, zgd);
925 		ASSERT((error && error != EINPROGRESS) ||
926 		    lr->lr_length <= zp->z_blksz);
927 		if (error == 0) {
928 			zil_add_vdev(zfsvfs->z_log,
929 			    DVA_GET_VDEV(BP_IDENTITY(&lr->lr_blkptr)));
930 		}
931 		/*
932 		 * If we get EINPROGRESS, then we need to wait for a
933 		 * write IO initiated by dmu_sync() to complete before
934 		 * we can release this dbuf.  We will finish everything
935 		 * up in the zfs_get_done() callback.
936 		 */
937 		if (error == EINPROGRESS)
938 			return (0);
939 		dmu_buf_rele(db, zgd);
940 		kmem_free(zgd, sizeof (zgd_t));
941 	}
942 out:
943 	zfs_range_unlock(rl);
944 	VN_RELE(ZTOV(zp));
945 	return (error);
946 }
947 
948 /*ARGSUSED*/
949 static int
950 zfs_access(vnode_t *vp, int mode, int flag, cred_t *cr,
951     caller_context_t *ct)
952 {
953 	znode_t *zp = VTOZ(vp);
954 	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
955 	int error;
956 
957 	ZFS_ENTER(zfsvfs);
958 	ZFS_VERIFY_ZP(zp);
959 
960 	if (flag & V_ACE_MASK)
961 		error = zfs_zaccess(zp, mode, flag, B_FALSE, cr);
962 	else
963 		error = zfs_zaccess_rwx(zp, mode, flag, cr);
964 
965 	ZFS_EXIT(zfsvfs);
966 	return (error);
967 }
968 
969 /*
970  * Lookup an entry in a directory, or an extended attribute directory.
971  * If it exists, return a held vnode reference for it.
972  *
973  *	IN:	dvp	- vnode of directory to search.
974  *		nm	- name of entry to lookup.
975  *		pnp	- full pathname to lookup [UNUSED].
976  *		flags	- LOOKUP_XATTR set if looking for an attribute.
977  *		rdir	- root directory vnode [UNUSED].
978  *		cr	- credentials of caller.
979  *		ct	- caller context
980  *		direntflags - directory lookup flags
981  *		realpnp - returned pathname.
982  *
983  *	OUT:	vpp	- vnode of located entry, NULL if not found.
984  *
985  *	RETURN:	0 if success
986  *		error code if failure
987  *
988  * Timestamps:
989  *	NA
990  */
991 /* ARGSUSED */
992 static int
993 zfs_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, struct pathname *pnp,
994     int flags, vnode_t *rdir, cred_t *cr,  caller_context_t *ct,
995     int *direntflags, pathname_t *realpnp)
996 {
997 	znode_t *zdp = VTOZ(dvp);
998 	zfsvfs_t *zfsvfs = zdp->z_zfsvfs;
999 	int	error;
1000 
1001 	ZFS_ENTER(zfsvfs);
1002 	ZFS_VERIFY_ZP(zdp);
1003 
1004 	*vpp = NULL;
1005 
1006 	if (flags & LOOKUP_XATTR) {
1007 		/*
1008 		 * If the xattr property is off, refuse the lookup request.
1009 		 */
1010 		if (!(zfsvfs->z_vfs->vfs_flag & VFS_XATTR)) {
1011 			ZFS_EXIT(zfsvfs);
1012 			return (EINVAL);
1013 		}
1014 
1015 		/*
1016 		 * We don't allow recursive attributes..
1017 		 * Maybe someday we will.
1018 		 */
1019 		if (zdp->z_phys->zp_flags & ZFS_XATTR) {
1020 			ZFS_EXIT(zfsvfs);
1021 			return (EINVAL);
1022 		}
1023 
1024 		if (error = zfs_get_xattrdir(VTOZ(dvp), vpp, cr, flags)) {
1025 			ZFS_EXIT(zfsvfs);
1026 			return (error);
1027 		}
1028 
1029 		/*
1030 		 * Do we have permission to get into attribute directory?
1031 		 */
1032 
1033 		if (error = zfs_zaccess(VTOZ(*vpp), ACE_EXECUTE, 0,
1034 		    B_FALSE, cr)) {
1035 			VN_RELE(*vpp);
1036 			*vpp = NULL;
1037 		}
1038 
1039 		ZFS_EXIT(zfsvfs);
1040 		return (error);
1041 	}
1042 
1043 	if (dvp->v_type != VDIR) {
1044 		ZFS_EXIT(zfsvfs);
1045 		return (ENOTDIR);
1046 	}
1047 
1048 	/*
1049 	 * Check accessibility of directory.
1050 	 */
1051 
1052 	if (error = zfs_zaccess(zdp, ACE_EXECUTE, 0, B_FALSE, cr)) {
1053 		ZFS_EXIT(zfsvfs);
1054 		return (error);
1055 	}
1056 
1057 	if (zfsvfs->z_utf8 && u8_validate(nm, strlen(nm),
1058 	    NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
1059 		ZFS_EXIT(zfsvfs);
1060 		return (EILSEQ);
1061 	}
1062 
1063 	error = zfs_dirlook(zdp, nm, vpp, flags, direntflags, realpnp);
1064 	if (error == 0) {
1065 		/*
1066 		 * Convert device special files
1067 		 */
1068 		if (IS_DEVVP(*vpp)) {
1069 			vnode_t	*svp;
1070 
1071 			svp = specvp(*vpp, (*vpp)->v_rdev, (*vpp)->v_type, cr);
1072 			VN_RELE(*vpp);
1073 			if (svp == NULL)
1074 				error = ENOSYS;
1075 			else
1076 				*vpp = svp;
1077 		}
1078 	}
1079 
1080 	ZFS_EXIT(zfsvfs);
1081 	return (error);
1082 }
1083 
1084 /*
1085  * Attempt to create a new entry in a directory.  If the entry
1086  * already exists, truncate the file if permissible, else return
1087  * an error.  Return the vp of the created or trunc'd file.
1088  *
1089  *	IN:	dvp	- vnode of directory to put new file entry in.
1090  *		name	- name of new file entry.
1091  *		vap	- attributes of new file.
1092  *		excl	- flag indicating exclusive or non-exclusive mode.
1093  *		mode	- mode to open file with.
1094  *		cr	- credentials of caller.
1095  *		flag	- large file flag [UNUSED].
1096  *		ct	- caller context
1097  *		vsecp 	- ACL to be set
1098  *
1099  *	OUT:	vpp	- vnode of created or trunc'd entry.
1100  *
1101  *	RETURN:	0 if success
1102  *		error code if failure
1103  *
1104  * Timestamps:
1105  *	dvp - ctime|mtime updated if new entry created
1106  *	 vp - ctime|mtime always, atime if new
1107  */
1108 
1109 /* ARGSUSED */
1110 static int
1111 zfs_create(vnode_t *dvp, char *name, vattr_t *vap, vcexcl_t excl,
1112     int mode, vnode_t **vpp, cred_t *cr, int flag, caller_context_t *ct,
1113     vsecattr_t *vsecp)
1114 {
1115 	znode_t		*zp, *dzp = VTOZ(dvp);
1116 	zfsvfs_t	*zfsvfs = dzp->z_zfsvfs;
1117 	zilog_t		*zilog;
1118 	objset_t	*os;
1119 	zfs_dirlock_t	*dl;
1120 	dmu_tx_t	*tx;
1121 	int		error;
1122 	zfs_acl_t	*aclp = NULL;
1123 	zfs_fuid_info_t *fuidp = NULL;
1124 
1125 	/*
1126 	 * If we have an ephemeral id, ACL, or XVATTR then
1127 	 * make sure file system is at proper version
1128 	 */
1129 
1130 	if (zfsvfs->z_use_fuids == B_FALSE &&
1131 	    (vsecp || (vap->va_mask & AT_XVATTR) ||
1132 	    IS_EPHEMERAL(crgetuid(cr)) || IS_EPHEMERAL(crgetgid(cr))))
1133 		return (EINVAL);
1134 
1135 	ZFS_ENTER(zfsvfs);
1136 	ZFS_VERIFY_ZP(dzp);
1137 	os = zfsvfs->z_os;
1138 	zilog = zfsvfs->z_log;
1139 
1140 	if (zfsvfs->z_utf8 && u8_validate(name, strlen(name),
1141 	    NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
1142 		ZFS_EXIT(zfsvfs);
1143 		return (EILSEQ);
1144 	}
1145 
1146 	if (vap->va_mask & AT_XVATTR) {
1147 		if ((error = secpolicy_xvattr((xvattr_t *)vap,
1148 		    crgetuid(cr), cr, vap->va_type)) != 0) {
1149 			ZFS_EXIT(zfsvfs);
1150 			return (error);
1151 		}
1152 	}
1153 top:
1154 	*vpp = NULL;
1155 
1156 	if ((vap->va_mode & VSVTX) && secpolicy_vnode_stky_modify(cr))
1157 		vap->va_mode &= ~VSVTX;
1158 
1159 	if (*name == '\0') {
1160 		/*
1161 		 * Null component name refers to the directory itself.
1162 		 */
1163 		VN_HOLD(dvp);
1164 		zp = dzp;
1165 		dl = NULL;
1166 		error = 0;
1167 	} else {
1168 		/* possible VN_HOLD(zp) */
1169 		int zflg = 0;
1170 
1171 		if (flag & FIGNORECASE)
1172 			zflg |= ZCILOOK;
1173 
1174 		error = zfs_dirent_lock(&dl, dzp, name, &zp, zflg,
1175 		    NULL, NULL);
1176 		if (error) {
1177 			if (strcmp(name, "..") == 0)
1178 				error = EISDIR;
1179 			ZFS_EXIT(zfsvfs);
1180 			if (aclp)
1181 				zfs_acl_free(aclp);
1182 			return (error);
1183 		}
1184 	}
1185 	if (vsecp && aclp == NULL) {
1186 		error = zfs_vsec_2_aclp(zfsvfs, vap->va_type, vsecp, &aclp);
1187 		if (error) {
1188 			ZFS_EXIT(zfsvfs);
1189 			if (dl)
1190 				zfs_dirent_unlock(dl);
1191 			return (error);
1192 		}
1193 	}
1194 
1195 	if (zp == NULL) {
1196 		uint64_t txtype;
1197 
1198 		/*
1199 		 * Create a new file object and update the directory
1200 		 * to reference it.
1201 		 */
1202 		if (error = zfs_zaccess(dzp, ACE_ADD_FILE, 0, B_FALSE, cr)) {
1203 			goto out;
1204 		}
1205 
1206 		/*
1207 		 * We only support the creation of regular files in
1208 		 * extended attribute directories.
1209 		 */
1210 		if ((dzp->z_phys->zp_flags & ZFS_XATTR) &&
1211 		    (vap->va_type != VREG)) {
1212 			error = EINVAL;
1213 			goto out;
1214 		}
1215 
1216 		tx = dmu_tx_create(os);
1217 		dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT);
1218 		if (zfsvfs->z_fuid_obj == 0) {
1219 			dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT);
1220 			dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0,
1221 			    SPA_MAXBLOCKSIZE);
1222 			dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, FALSE, NULL);
1223 		} else {
1224 			dmu_tx_hold_bonus(tx, zfsvfs->z_fuid_obj);
1225 			dmu_tx_hold_write(tx, zfsvfs->z_fuid_obj, 0,
1226 			    SPA_MAXBLOCKSIZE);
1227 		}
1228 		dmu_tx_hold_bonus(tx, dzp->z_id);
1229 		dmu_tx_hold_zap(tx, dzp->z_id, TRUE, name);
1230 		if ((dzp->z_phys->zp_flags & ZFS_INHERIT_ACE) || aclp) {
1231 			dmu_tx_hold_write(tx, DMU_NEW_OBJECT,
1232 			    0, SPA_MAXBLOCKSIZE);
1233 		}
1234 		error = dmu_tx_assign(tx, zfsvfs->z_assign);
1235 		if (error) {
1236 			zfs_dirent_unlock(dl);
1237 			if (error == ERESTART &&
1238 			    zfsvfs->z_assign == TXG_NOWAIT) {
1239 				dmu_tx_wait(tx);
1240 				dmu_tx_abort(tx);
1241 				goto top;
1242 			}
1243 			dmu_tx_abort(tx);
1244 			ZFS_EXIT(zfsvfs);
1245 			if (aclp)
1246 				zfs_acl_free(aclp);
1247 			return (error);
1248 		}
1249 		zfs_mknode(dzp, vap, tx, cr, 0, &zp, 0, aclp, &fuidp);
1250 		(void) zfs_link_create(dl, zp, tx, ZNEW);
1251 		txtype = zfs_log_create_txtype(Z_FILE, vsecp, vap);
1252 		if (flag & FIGNORECASE)
1253 			txtype |= TX_CI;
1254 		zfs_log_create(zilog, tx, txtype, dzp, zp, name,
1255 		    vsecp, fuidp, vap);
1256 		if (fuidp)
1257 			zfs_fuid_info_free(fuidp);
1258 		dmu_tx_commit(tx);
1259 	} else {
1260 		int aflags = (flag & FAPPEND) ? V_APPEND : 0;
1261 
1262 		/*
1263 		 * A directory entry already exists for this name.
1264 		 */
1265 		/*
1266 		 * Can't truncate an existing file if in exclusive mode.
1267 		 */
1268 		if (excl == EXCL) {
1269 			error = EEXIST;
1270 			goto out;
1271 		}
1272 		/*
1273 		 * Can't open a directory for writing.
1274 		 */
1275 		if ((ZTOV(zp)->v_type == VDIR) && (mode & S_IWRITE)) {
1276 			error = EISDIR;
1277 			goto out;
1278 		}
1279 		/*
1280 		 * Verify requested access to file.
1281 		 */
1282 		if (mode && (error = zfs_zaccess_rwx(zp, mode, aflags, cr))) {
1283 			goto out;
1284 		}
1285 
1286 		mutex_enter(&dzp->z_lock);
1287 		dzp->z_seq++;
1288 		mutex_exit(&dzp->z_lock);
1289 
1290 		/*
1291 		 * Truncate regular files if requested.
1292 		 */
1293 		if ((ZTOV(zp)->v_type == VREG) &&
1294 		    (vap->va_mask & AT_SIZE) && (vap->va_size == 0)) {
1295 			error = zfs_freesp(zp, 0, 0, mode, TRUE);
1296 			if (error == ERESTART &&
1297 			    zfsvfs->z_assign == TXG_NOWAIT) {
1298 				/* NB: we already did dmu_tx_wait() */
1299 				zfs_dirent_unlock(dl);
1300 				VN_RELE(ZTOV(zp));
1301 				goto top;
1302 			}
1303 
1304 			if (error == 0) {
1305 				vnevent_create(ZTOV(zp), ct);
1306 			}
1307 		}
1308 	}
1309 out:
1310 
1311 	if (dl)
1312 		zfs_dirent_unlock(dl);
1313 
1314 	if (error) {
1315 		if (zp)
1316 			VN_RELE(ZTOV(zp));
1317 	} else {
1318 		*vpp = ZTOV(zp);
1319 		/*
1320 		 * If vnode is for a device return a specfs vnode instead.
1321 		 */
1322 		if (IS_DEVVP(*vpp)) {
1323 			struct vnode *svp;
1324 
1325 			svp = specvp(*vpp, (*vpp)->v_rdev, (*vpp)->v_type, cr);
1326 			VN_RELE(*vpp);
1327 			if (svp == NULL) {
1328 				error = ENOSYS;
1329 			}
1330 			*vpp = svp;
1331 		}
1332 	}
1333 	if (aclp)
1334 		zfs_acl_free(aclp);
1335 
1336 	ZFS_EXIT(zfsvfs);
1337 	return (error);
1338 }
1339 
1340 /*
1341  * Remove an entry from a directory.
1342  *
1343  *	IN:	dvp	- vnode of directory to remove entry from.
1344  *		name	- name of entry to remove.
1345  *		cr	- credentials of caller.
1346  *		ct	- caller context
1347  *		flags	- case flags
1348  *
1349  *	RETURN:	0 if success
1350  *		error code if failure
1351  *
1352  * Timestamps:
1353  *	dvp - ctime|mtime
1354  *	 vp - ctime (if nlink > 0)
1355  */
1356 /*ARGSUSED*/
1357 static int
1358 zfs_remove(vnode_t *dvp, char *name, cred_t *cr, caller_context_t *ct,
1359     int flags)
1360 {
1361 	znode_t		*zp, *dzp = VTOZ(dvp);
1362 	znode_t		*xzp = NULL;
1363 	vnode_t		*vp;
1364 	zfsvfs_t	*zfsvfs = dzp->z_zfsvfs;
1365 	zilog_t		*zilog;
1366 	uint64_t	acl_obj, xattr_obj;
1367 	zfs_dirlock_t	*dl;
1368 	dmu_tx_t	*tx;
1369 	boolean_t	may_delete_now, delete_now = FALSE;
1370 	boolean_t	unlinked;
1371 	uint64_t	txtype;
1372 	pathname_t	*realnmp = NULL;
1373 	pathname_t	realnm;
1374 	int		error;
1375 	int		zflg = ZEXISTS;
1376 
1377 	ZFS_ENTER(zfsvfs);
1378 	ZFS_VERIFY_ZP(dzp);
1379 	zilog = zfsvfs->z_log;
1380 
1381 	if (flags & FIGNORECASE) {
1382 		zflg |= ZCILOOK;
1383 		pn_alloc(&realnm);
1384 		realnmp = &realnm;
1385 	}
1386 
1387 top:
1388 	/*
1389 	 * Attempt to lock directory; fail if entry doesn't exist.
1390 	 */
1391 	if (error = zfs_dirent_lock(&dl, dzp, name, &zp, zflg,
1392 	    NULL, realnmp)) {
1393 		if (realnmp)
1394 			pn_free(realnmp);
1395 		ZFS_EXIT(zfsvfs);
1396 		return (error);
1397 	}
1398 
1399 	vp = ZTOV(zp);
1400 
1401 	if (error = zfs_zaccess_delete(dzp, zp, cr)) {
1402 		goto out;
1403 	}
1404 
1405 	/*
1406 	 * Need to use rmdir for removing directories.
1407 	 */
1408 	if (vp->v_type == VDIR) {
1409 		error = EPERM;
1410 		goto out;
1411 	}
1412 
1413 	vnevent_remove(vp, dvp, name, ct);
1414 
1415 	if (realnmp)
1416 		dnlc_remove(dvp, realnmp->pn_path);
1417 	else
1418 		dnlc_remove(dvp, name);
1419 
1420 	mutex_enter(&vp->v_lock);
1421 	may_delete_now = vp->v_count == 1 && !vn_has_cached_data(vp);
1422 	mutex_exit(&vp->v_lock);
1423 
1424 	/*
1425 	 * We may delete the znode now, or we may put it in the unlinked set;
1426 	 * it depends on whether we're the last link, and on whether there are
1427 	 * other holds on the vnode.  So we dmu_tx_hold() the right things to
1428 	 * allow for either case.
1429 	 */
1430 	tx = dmu_tx_create(zfsvfs->z_os);
1431 	dmu_tx_hold_zap(tx, dzp->z_id, FALSE, name);
1432 	dmu_tx_hold_bonus(tx, zp->z_id);
1433 	if (may_delete_now)
1434 		dmu_tx_hold_free(tx, zp->z_id, 0, DMU_OBJECT_END);
1435 
1436 	/* are there any extended attributes? */
1437 	if ((xattr_obj = zp->z_phys->zp_xattr) != 0) {
1438 		/* XXX - do we need this if we are deleting? */
1439 		dmu_tx_hold_bonus(tx, xattr_obj);
1440 	}
1441 
1442 	/* are there any additional acls */
1443 	if ((acl_obj = zp->z_phys->zp_acl.z_acl_extern_obj) != 0 &&
1444 	    may_delete_now)
1445 		dmu_tx_hold_free(tx, acl_obj, 0, DMU_OBJECT_END);
1446 
1447 	/* charge as an update -- would be nice not to charge at all */
1448 	dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
1449 
1450 	error = dmu_tx_assign(tx, zfsvfs->z_assign);
1451 	if (error) {
1452 		zfs_dirent_unlock(dl);
1453 		VN_RELE(vp);
1454 		if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) {
1455 			dmu_tx_wait(tx);
1456 			dmu_tx_abort(tx);
1457 			goto top;
1458 		}
1459 		if (realnmp)
1460 			pn_free(realnmp);
1461 		dmu_tx_abort(tx);
1462 		ZFS_EXIT(zfsvfs);
1463 		return (error);
1464 	}
1465 
1466 	/*
1467 	 * Remove the directory entry.
1468 	 */
1469 	error = zfs_link_destroy(dl, zp, tx, zflg, &unlinked);
1470 
1471 	if (error) {
1472 		dmu_tx_commit(tx);
1473 		goto out;
1474 	}
1475 
1476 	if (unlinked) {
1477 		mutex_enter(&vp->v_lock);
1478 		delete_now = may_delete_now &&
1479 		    vp->v_count == 1 && !vn_has_cached_data(vp) &&
1480 		    zp->z_phys->zp_xattr == xattr_obj &&
1481 		    zp->z_phys->zp_acl.z_acl_extern_obj == acl_obj;
1482 		mutex_exit(&vp->v_lock);
1483 	}
1484 
1485 	if (delete_now) {
1486 		if (zp->z_phys->zp_xattr) {
1487 			error = zfs_zget(zfsvfs, zp->z_phys->zp_xattr, &xzp);
1488 			ASSERT3U(error, ==, 0);
1489 			ASSERT3U(xzp->z_phys->zp_links, ==, 2);
1490 			dmu_buf_will_dirty(xzp->z_dbuf, tx);
1491 			mutex_enter(&xzp->z_lock);
1492 			xzp->z_unlinked = 1;
1493 			xzp->z_phys->zp_links = 0;
1494 			mutex_exit(&xzp->z_lock);
1495 			zfs_unlinked_add(xzp, tx);
1496 			zp->z_phys->zp_xattr = 0; /* probably unnecessary */
1497 		}
1498 		mutex_enter(&zp->z_lock);
1499 		mutex_enter(&vp->v_lock);
1500 		vp->v_count--;
1501 		ASSERT3U(vp->v_count, ==, 0);
1502 		mutex_exit(&vp->v_lock);
1503 		mutex_exit(&zp->z_lock);
1504 		zfs_znode_delete(zp, tx);
1505 		VFS_RELE(zfsvfs->z_vfs);
1506 	} else if (unlinked) {
1507 		zfs_unlinked_add(zp, tx);
1508 	}
1509 
1510 	txtype = TX_REMOVE;
1511 	if (flags & FIGNORECASE)
1512 		txtype |= TX_CI;
1513 	zfs_log_remove(zilog, tx, txtype, dzp, name);
1514 
1515 	dmu_tx_commit(tx);
1516 out:
1517 	if (realnmp)
1518 		pn_free(realnmp);
1519 
1520 	zfs_dirent_unlock(dl);
1521 
1522 	if (!delete_now) {
1523 		VN_RELE(vp);
1524 	} else if (xzp) {
1525 		/* this rele delayed to prevent nesting transactions */
1526 		VN_RELE(ZTOV(xzp));
1527 	}
1528 
1529 	ZFS_EXIT(zfsvfs);
1530 	return (error);
1531 }
1532 
1533 /*
1534  * Create a new directory and insert it into dvp using the name
1535  * provided.  Return a pointer to the inserted directory.
1536  *
1537  *	IN:	dvp	- vnode of directory to add subdir to.
1538  *		dirname	- name of new directory.
1539  *		vap	- attributes of new directory.
1540  *		cr	- credentials of caller.
1541  *		ct	- caller context
1542  *		vsecp	- ACL to be set
1543  *
1544  *	OUT:	vpp	- vnode of created directory.
1545  *
1546  *	RETURN:	0 if success
1547  *		error code if failure
1548  *
1549  * Timestamps:
1550  *	dvp - ctime|mtime updated
1551  *	 vp - ctime|mtime|atime updated
1552  */
1553 /*ARGSUSED*/
1554 static int
1555 zfs_mkdir(vnode_t *dvp, char *dirname, vattr_t *vap, vnode_t **vpp, cred_t *cr,
1556     caller_context_t *ct, int flags, vsecattr_t *vsecp)
1557 {
1558 	znode_t		*zp, *dzp = VTOZ(dvp);
1559 	zfsvfs_t	*zfsvfs = dzp->z_zfsvfs;
1560 	zilog_t		*zilog;
1561 	zfs_dirlock_t	*dl;
1562 	uint64_t	txtype;
1563 	dmu_tx_t	*tx;
1564 	int		error;
1565 	zfs_acl_t	*aclp = NULL;
1566 	zfs_fuid_info_t	*fuidp = NULL;
1567 	int		zf = ZNEW;
1568 
1569 	ASSERT(vap->va_type == VDIR);
1570 
1571 	/*
1572 	 * If we have an ephemeral id, ACL, or XVATTR then
1573 	 * make sure file system is at proper version
1574 	 */
1575 
1576 	if (zfsvfs->z_use_fuids == B_FALSE &&
1577 	    (vsecp || (vap->va_mask & AT_XVATTR) || IS_EPHEMERAL(crgetuid(cr))||
1578 	    IS_EPHEMERAL(crgetgid(cr))))
1579 		return (EINVAL);
1580 
1581 	ZFS_ENTER(zfsvfs);
1582 	ZFS_VERIFY_ZP(dzp);
1583 	zilog = zfsvfs->z_log;
1584 
1585 	if (dzp->z_phys->zp_flags & ZFS_XATTR) {
1586 		ZFS_EXIT(zfsvfs);
1587 		return (EINVAL);
1588 	}
1589 
1590 	if (zfsvfs->z_utf8 && u8_validate(dirname,
1591 	    strlen(dirname), NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
1592 		ZFS_EXIT(zfsvfs);
1593 		return (EILSEQ);
1594 	}
1595 	if (flags & FIGNORECASE)
1596 		zf |= ZCILOOK;
1597 
1598 	if (vap->va_mask & AT_XVATTR)
1599 		if ((error = secpolicy_xvattr((xvattr_t *)vap,
1600 		    crgetuid(cr), cr, vap->va_type)) != 0) {
1601 			ZFS_EXIT(zfsvfs);
1602 			return (error);
1603 		}
1604 
1605 	/*
1606 	 * First make sure the new directory doesn't exist.
1607 	 */
1608 top:
1609 	*vpp = NULL;
1610 
1611 	if (error = zfs_dirent_lock(&dl, dzp, dirname, &zp, zf,
1612 	    NULL, NULL)) {
1613 		ZFS_EXIT(zfsvfs);
1614 		return (error);
1615 	}
1616 
1617 	if (error = zfs_zaccess(dzp, ACE_ADD_SUBDIRECTORY, 0, B_FALSE, cr)) {
1618 		zfs_dirent_unlock(dl);
1619 		ZFS_EXIT(zfsvfs);
1620 		return (error);
1621 	}
1622 
1623 	if (vsecp && aclp == NULL) {
1624 		error = zfs_vsec_2_aclp(zfsvfs, vap->va_type, vsecp, &aclp);
1625 		if (error) {
1626 			zfs_dirent_unlock(dl);
1627 			ZFS_EXIT(zfsvfs);
1628 			return (error);
1629 		}
1630 	}
1631 	/*
1632 	 * Add a new entry to the directory.
1633 	 */
1634 	tx = dmu_tx_create(zfsvfs->z_os);
1635 	dmu_tx_hold_zap(tx, dzp->z_id, TRUE, dirname);
1636 	dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
1637 	if (zfsvfs->z_fuid_obj == 0) {
1638 		dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT);
1639 		dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0,
1640 		    SPA_MAXBLOCKSIZE);
1641 		dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, FALSE, NULL);
1642 	} else {
1643 		dmu_tx_hold_bonus(tx, zfsvfs->z_fuid_obj);
1644 		dmu_tx_hold_write(tx, zfsvfs->z_fuid_obj, 0,
1645 		    SPA_MAXBLOCKSIZE);
1646 	}
1647 	if ((dzp->z_phys->zp_flags & ZFS_INHERIT_ACE) || aclp)
1648 		dmu_tx_hold_write(tx, DMU_NEW_OBJECT,
1649 		    0, SPA_MAXBLOCKSIZE);
1650 	error = dmu_tx_assign(tx, zfsvfs->z_assign);
1651 	if (error) {
1652 		zfs_dirent_unlock(dl);
1653 		if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) {
1654 			dmu_tx_wait(tx);
1655 			dmu_tx_abort(tx);
1656 			goto top;
1657 		}
1658 		dmu_tx_abort(tx);
1659 		ZFS_EXIT(zfsvfs);
1660 		if (aclp)
1661 			zfs_acl_free(aclp);
1662 		return (error);
1663 	}
1664 
1665 	/*
1666 	 * Create new node.
1667 	 */
1668 	zfs_mknode(dzp, vap, tx, cr, 0, &zp, 0, aclp, &fuidp);
1669 
1670 	if (aclp)
1671 		zfs_acl_free(aclp);
1672 
1673 	/*
1674 	 * Now put new name in parent dir.
1675 	 */
1676 	(void) zfs_link_create(dl, zp, tx, ZNEW);
1677 
1678 	*vpp = ZTOV(zp);
1679 
1680 	txtype = zfs_log_create_txtype(Z_DIR, vsecp, vap);
1681 	if (flags & FIGNORECASE)
1682 		txtype |= TX_CI;
1683 	zfs_log_create(zilog, tx, txtype, dzp, zp, dirname, vsecp, fuidp, vap);
1684 
1685 	if (fuidp)
1686 		zfs_fuid_info_free(fuidp);
1687 	dmu_tx_commit(tx);
1688 
1689 	zfs_dirent_unlock(dl);
1690 
1691 	ZFS_EXIT(zfsvfs);
1692 	return (0);
1693 }
1694 
1695 /*
1696  * Remove a directory subdir entry.  If the current working
1697  * directory is the same as the subdir to be removed, the
1698  * remove will fail.
1699  *
1700  *	IN:	dvp	- vnode of directory to remove from.
1701  *		name	- name of directory to be removed.
1702  *		cwd	- vnode of current working directory.
1703  *		cr	- credentials of caller.
1704  *		ct	- caller context
1705  *		flags	- case flags
1706  *
1707  *	RETURN:	0 if success
1708  *		error code if failure
1709  *
1710  * Timestamps:
1711  *	dvp - ctime|mtime updated
1712  */
1713 /*ARGSUSED*/
1714 static int
1715 zfs_rmdir(vnode_t *dvp, char *name, vnode_t *cwd, cred_t *cr,
1716     caller_context_t *ct, int flags)
1717 {
1718 	znode_t		*dzp = VTOZ(dvp);
1719 	znode_t		*zp;
1720 	vnode_t		*vp;
1721 	zfsvfs_t	*zfsvfs = dzp->z_zfsvfs;
1722 	zilog_t		*zilog;
1723 	zfs_dirlock_t	*dl;
1724 	dmu_tx_t	*tx;
1725 	int		error;
1726 	int		zflg = ZEXISTS;
1727 
1728 	ZFS_ENTER(zfsvfs);
1729 	ZFS_VERIFY_ZP(dzp);
1730 	zilog = zfsvfs->z_log;
1731 
1732 	if (flags & FIGNORECASE)
1733 		zflg |= ZCILOOK;
1734 top:
1735 	zp = NULL;
1736 
1737 	/*
1738 	 * Attempt to lock directory; fail if entry doesn't exist.
1739 	 */
1740 	if (error = zfs_dirent_lock(&dl, dzp, name, &zp, zflg,
1741 	    NULL, NULL)) {
1742 		ZFS_EXIT(zfsvfs);
1743 		return (error);
1744 	}
1745 
1746 	vp = ZTOV(zp);
1747 
1748 	if (error = zfs_zaccess_delete(dzp, zp, cr)) {
1749 		goto out;
1750 	}
1751 
1752 	if (vp->v_type != VDIR) {
1753 		error = ENOTDIR;
1754 		goto out;
1755 	}
1756 
1757 	if (vp == cwd) {
1758 		error = EINVAL;
1759 		goto out;
1760 	}
1761 
1762 	vnevent_rmdir(vp, dvp, name, ct);
1763 
1764 	/*
1765 	 * Grab a lock on the directory to make sure that noone is
1766 	 * trying to add (or lookup) entries while we are removing it.
1767 	 */
1768 	rw_enter(&zp->z_name_lock, RW_WRITER);
1769 
1770 	/*
1771 	 * Grab a lock on the parent pointer to make sure we play well
1772 	 * with the treewalk and directory rename code.
1773 	 */
1774 	rw_enter(&zp->z_parent_lock, RW_WRITER);
1775 
1776 	tx = dmu_tx_create(zfsvfs->z_os);
1777 	dmu_tx_hold_zap(tx, dzp->z_id, FALSE, name);
1778 	dmu_tx_hold_bonus(tx, zp->z_id);
1779 	dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
1780 	error = dmu_tx_assign(tx, zfsvfs->z_assign);
1781 	if (error) {
1782 		rw_exit(&zp->z_parent_lock);
1783 		rw_exit(&zp->z_name_lock);
1784 		zfs_dirent_unlock(dl);
1785 		VN_RELE(vp);
1786 		if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) {
1787 			dmu_tx_wait(tx);
1788 			dmu_tx_abort(tx);
1789 			goto top;
1790 		}
1791 		dmu_tx_abort(tx);
1792 		ZFS_EXIT(zfsvfs);
1793 		return (error);
1794 	}
1795 
1796 	error = zfs_link_destroy(dl, zp, tx, zflg, NULL);
1797 
1798 	if (error == 0) {
1799 		uint64_t txtype = TX_RMDIR;
1800 		if (flags & FIGNORECASE)
1801 			txtype |= TX_CI;
1802 		zfs_log_remove(zilog, tx, txtype, dzp, name);
1803 	}
1804 
1805 	dmu_tx_commit(tx);
1806 
1807 	rw_exit(&zp->z_parent_lock);
1808 	rw_exit(&zp->z_name_lock);
1809 out:
1810 	zfs_dirent_unlock(dl);
1811 
1812 	VN_RELE(vp);
1813 
1814 	ZFS_EXIT(zfsvfs);
1815 	return (error);
1816 }
1817 
1818 /*
1819  * Read as many directory entries as will fit into the provided
1820  * buffer from the given directory cursor position (specified in
1821  * the uio structure.
1822  *
1823  *	IN:	vp	- vnode of directory to read.
1824  *		uio	- structure supplying read location, range info,
1825  *			  and return buffer.
1826  *		cr	- credentials of caller.
1827  *		ct	- caller context
1828  *		flags	- case flags
1829  *
1830  *	OUT:	uio	- updated offset and range, buffer filled.
1831  *		eofp	- set to true if end-of-file detected.
1832  *
1833  *	RETURN:	0 if success
1834  *		error code if failure
1835  *
1836  * Timestamps:
1837  *	vp - atime updated
1838  *
1839  * Note that the low 4 bits of the cookie returned by zap is always zero.
1840  * This allows us to use the low range for "special" directory entries:
1841  * We use 0 for '.', and 1 for '..'.  If this is the root of the filesystem,
1842  * we use the offset 2 for the '.zfs' directory.
1843  */
1844 /* ARGSUSED */
1845 static int
1846 zfs_readdir(vnode_t *vp, uio_t *uio, cred_t *cr, int *eofp,
1847     caller_context_t *ct, int flags)
1848 {
1849 	znode_t		*zp = VTOZ(vp);
1850 	iovec_t		*iovp;
1851 	edirent_t	*eodp;
1852 	dirent64_t	*odp;
1853 	zfsvfs_t	*zfsvfs = zp->z_zfsvfs;
1854 	objset_t	*os;
1855 	caddr_t		outbuf;
1856 	size_t		bufsize;
1857 	zap_cursor_t	zc;
1858 	zap_attribute_t	zap;
1859 	uint_t		bytes_wanted;
1860 	uint64_t	offset; /* must be unsigned; checks for < 1 */
1861 	int		local_eof;
1862 	int		outcount;
1863 	int		error;
1864 	uint8_t		prefetch;
1865 
1866 	ZFS_ENTER(zfsvfs);
1867 	ZFS_VERIFY_ZP(zp);
1868 
1869 	/*
1870 	 * If we are not given an eof variable,
1871 	 * use a local one.
1872 	 */
1873 	if (eofp == NULL)
1874 		eofp = &local_eof;
1875 
1876 	/*
1877 	 * Check for valid iov_len.
1878 	 */
1879 	if (uio->uio_iov->iov_len <= 0) {
1880 		ZFS_EXIT(zfsvfs);
1881 		return (EINVAL);
1882 	}
1883 
1884 	/*
1885 	 * Quit if directory has been removed (posix)
1886 	 */
1887 	if ((*eofp = zp->z_unlinked) != 0) {
1888 		ZFS_EXIT(zfsvfs);
1889 		return (0);
1890 	}
1891 
1892 	error = 0;
1893 	os = zfsvfs->z_os;
1894 	offset = uio->uio_loffset;
1895 	prefetch = zp->z_zn_prefetch;
1896 
1897 	/*
1898 	 * Initialize the iterator cursor.
1899 	 */
1900 	if (offset <= 3) {
1901 		/*
1902 		 * Start iteration from the beginning of the directory.
1903 		 */
1904 		zap_cursor_init(&zc, os, zp->z_id);
1905 	} else {
1906 		/*
1907 		 * The offset is a serialized cursor.
1908 		 */
1909 		zap_cursor_init_serialized(&zc, os, zp->z_id, offset);
1910 	}
1911 
1912 	/*
1913 	 * Get space to change directory entries into fs independent format.
1914 	 */
1915 	iovp = uio->uio_iov;
1916 	bytes_wanted = iovp->iov_len;
1917 	if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1) {
1918 		bufsize = bytes_wanted;
1919 		outbuf = kmem_alloc(bufsize, KM_SLEEP);
1920 		odp = (struct dirent64 *)outbuf;
1921 	} else {
1922 		bufsize = bytes_wanted;
1923 		odp = (struct dirent64 *)iovp->iov_base;
1924 	}
1925 	eodp = (struct edirent *)odp;
1926 
1927 	/*
1928 	 * Transform to file-system independent format
1929 	 */
1930 	outcount = 0;
1931 	while (outcount < bytes_wanted) {
1932 		ino64_t objnum;
1933 		ushort_t reclen;
1934 		off64_t *next;
1935 
1936 		/*
1937 		 * Special case `.', `..', and `.zfs'.
1938 		 */
1939 		if (offset == 0) {
1940 			(void) strcpy(zap.za_name, ".");
1941 			zap.za_normalization_conflict = 0;
1942 			objnum = zp->z_id;
1943 		} else if (offset == 1) {
1944 			(void) strcpy(zap.za_name, "..");
1945 			zap.za_normalization_conflict = 0;
1946 			objnum = zp->z_phys->zp_parent;
1947 		} else if (offset == 2 && zfs_show_ctldir(zp)) {
1948 			(void) strcpy(zap.za_name, ZFS_CTLDIR_NAME);
1949 			zap.za_normalization_conflict = 0;
1950 			objnum = ZFSCTL_INO_ROOT;
1951 		} else {
1952 			/*
1953 			 * Grab next entry.
1954 			 */
1955 			if (error = zap_cursor_retrieve(&zc, &zap)) {
1956 				if ((*eofp = (error == ENOENT)) != 0)
1957 					break;
1958 				else
1959 					goto update;
1960 			}
1961 
1962 			if (zap.za_integer_length != 8 ||
1963 			    zap.za_num_integers != 1) {
1964 				cmn_err(CE_WARN, "zap_readdir: bad directory "
1965 				    "entry, obj = %lld, offset = %lld\n",
1966 				    (u_longlong_t)zp->z_id,
1967 				    (u_longlong_t)offset);
1968 				error = ENXIO;
1969 				goto update;
1970 			}
1971 
1972 			objnum = ZFS_DIRENT_OBJ(zap.za_first_integer);
1973 			/*
1974 			 * MacOS X can extract the object type here such as:
1975 			 * uint8_t type = ZFS_DIRENT_TYPE(zap.za_first_integer);
1976 			 */
1977 		}
1978 
1979 		if (flags & V_RDDIR_ENTFLAGS)
1980 			reclen = EDIRENT_RECLEN(strlen(zap.za_name));
1981 		else
1982 			reclen = DIRENT64_RECLEN(strlen(zap.za_name));
1983 
1984 		/*
1985 		 * Will this entry fit in the buffer?
1986 		 */
1987 		if (outcount + reclen > bufsize) {
1988 			/*
1989 			 * Did we manage to fit anything in the buffer?
1990 			 */
1991 			if (!outcount) {
1992 				error = EINVAL;
1993 				goto update;
1994 			}
1995 			break;
1996 		}
1997 		if (flags & V_RDDIR_ENTFLAGS) {
1998 			/*
1999 			 * Add extended flag entry:
2000 			 */
2001 			eodp->ed_ino = objnum;
2002 			eodp->ed_reclen = reclen;
2003 			/* NOTE: ed_off is the offset for the *next* entry */
2004 			next = &(eodp->ed_off);
2005 			eodp->ed_eflags = zap.za_normalization_conflict ?
2006 			    ED_CASE_CONFLICT : 0;
2007 			(void) strncpy(eodp->ed_name, zap.za_name,
2008 			    EDIRENT_NAMELEN(reclen));
2009 			eodp = (edirent_t *)((intptr_t)eodp + reclen);
2010 		} else {
2011 			/*
2012 			 * Add normal entry:
2013 			 */
2014 			odp->d_ino = objnum;
2015 			odp->d_reclen = reclen;
2016 			/* NOTE: d_off is the offset for the *next* entry */
2017 			next = &(odp->d_off);
2018 			(void) strncpy(odp->d_name, zap.za_name,
2019 			    DIRENT64_NAMELEN(reclen));
2020 			odp = (dirent64_t *)((intptr_t)odp + reclen);
2021 		}
2022 		outcount += reclen;
2023 
2024 		ASSERT(outcount <= bufsize);
2025 
2026 		/* Prefetch znode */
2027 		if (prefetch)
2028 			dmu_prefetch(os, objnum, 0, 0);
2029 
2030 		/*
2031 		 * Move to the next entry, fill in the previous offset.
2032 		 */
2033 		if (offset > 2 || (offset == 2 && !zfs_show_ctldir(zp))) {
2034 			zap_cursor_advance(&zc);
2035 			offset = zap_cursor_serialize(&zc);
2036 		} else {
2037 			offset += 1;
2038 		}
2039 		*next = offset;
2040 	}
2041 	zp->z_zn_prefetch = B_FALSE; /* a lookup will re-enable pre-fetching */
2042 
2043 	if (uio->uio_segflg == UIO_SYSSPACE && uio->uio_iovcnt == 1) {
2044 		iovp->iov_base += outcount;
2045 		iovp->iov_len -= outcount;
2046 		uio->uio_resid -= outcount;
2047 	} else if (error = uiomove(outbuf, (long)outcount, UIO_READ, uio)) {
2048 		/*
2049 		 * Reset the pointer.
2050 		 */
2051 		offset = uio->uio_loffset;
2052 	}
2053 
2054 update:
2055 	zap_cursor_fini(&zc);
2056 	if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1)
2057 		kmem_free(outbuf, bufsize);
2058 
2059 	if (error == ENOENT)
2060 		error = 0;
2061 
2062 	ZFS_ACCESSTIME_STAMP(zfsvfs, zp);
2063 
2064 	uio->uio_loffset = offset;
2065 	ZFS_EXIT(zfsvfs);
2066 	return (error);
2067 }
2068 
2069 ulong_t zfs_fsync_sync_cnt = 4;
2070 
2071 static int
2072 zfs_fsync(vnode_t *vp, int syncflag, cred_t *cr, caller_context_t *ct)
2073 {
2074 	znode_t	*zp = VTOZ(vp);
2075 	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
2076 
2077 	/*
2078 	 * Regardless of whether this is required for standards conformance,
2079 	 * this is the logical behavior when fsync() is called on a file with
2080 	 * dirty pages.  We use B_ASYNC since the ZIL transactions are already
2081 	 * going to be pushed out as part of the zil_commit().
2082 	 */
2083 	if (vn_has_cached_data(vp) && !(syncflag & FNODSYNC) &&
2084 	    (vp->v_type == VREG) && !(IS_SWAPVP(vp)))
2085 		(void) VOP_PUTPAGE(vp, (offset_t)0, (size_t)0, B_ASYNC, cr, ct);
2086 
2087 	(void) tsd_set(zfs_fsyncer_key, (void *)zfs_fsync_sync_cnt);
2088 
2089 	ZFS_ENTER(zfsvfs);
2090 	ZFS_VERIFY_ZP(zp);
2091 	zil_commit(zfsvfs->z_log, zp->z_last_itx, zp->z_id);
2092 	ZFS_EXIT(zfsvfs);
2093 	return (0);
2094 }
2095 
2096 
2097 /*
2098  * Get the requested file attributes and place them in the provided
2099  * vattr structure.
2100  *
2101  *	IN:	vp	- vnode of file.
2102  *		vap	- va_mask identifies requested attributes.
2103  *			  If AT_XVATTR set, then optional attrs are requested
2104  *		flags	- ATTR_NOACLCHECK (CIFS server context)
2105  *		cr	- credentials of caller.
2106  *		ct	- caller context
2107  *
2108  *	OUT:	vap	- attribute values.
2109  *
2110  *	RETURN:	0 (always succeeds)
2111  */
2112 /* ARGSUSED */
2113 static int
2114 zfs_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
2115     caller_context_t *ct)
2116 {
2117 	znode_t *zp = VTOZ(vp);
2118 	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
2119 	znode_phys_t *pzp;
2120 	int	error = 0;
2121 	uint64_t links;
2122 	xvattr_t *xvap = (xvattr_t *)vap;	/* vap may be an xvattr_t * */
2123 	xoptattr_t *xoap = NULL;
2124 	boolean_t skipaclchk = (flags & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE;
2125 
2126 	ZFS_ENTER(zfsvfs);
2127 	ZFS_VERIFY_ZP(zp);
2128 	pzp = zp->z_phys;
2129 
2130 	mutex_enter(&zp->z_lock);
2131 
2132 	/*
2133 	 * If ACL is trivial don't bother looking for ACE_READ_ATTRIBUTES.
2134 	 * Also, if we are the owner don't bother, since owner should
2135 	 * always be allowed to read basic attributes of file.
2136 	 */
2137 	if (!(pzp->zp_flags & ZFS_ACL_TRIVIAL) &&
2138 	    (pzp->zp_uid != crgetuid(cr))) {
2139 		if (error = zfs_zaccess(zp, ACE_READ_ATTRIBUTES, 0,
2140 		    skipaclchk, cr)) {
2141 			mutex_exit(&zp->z_lock);
2142 			ZFS_EXIT(zfsvfs);
2143 			return (error);
2144 		}
2145 	}
2146 
2147 	/*
2148 	 * Return all attributes.  It's cheaper to provide the answer
2149 	 * than to determine whether we were asked the question.
2150 	 */
2151 
2152 	vap->va_type = vp->v_type;
2153 	vap->va_mode = pzp->zp_mode & MODEMASK;
2154 	zfs_fuid_map_ids(zp, &vap->va_uid, &vap->va_gid);
2155 	vap->va_fsid = zp->z_zfsvfs->z_vfs->vfs_dev;
2156 	vap->va_nodeid = zp->z_id;
2157 	if ((vp->v_flag & VROOT) && zfs_show_ctldir(zp))
2158 		links = pzp->zp_links + 1;
2159 	else
2160 		links = pzp->zp_links;
2161 	vap->va_nlink = MIN(links, UINT32_MAX);	/* nlink_t limit! */
2162 	vap->va_size = pzp->zp_size;
2163 	vap->va_rdev = vp->v_rdev;
2164 	vap->va_seq = zp->z_seq;
2165 
2166 	/*
2167 	 * Add in any requested optional attributes and the create time.
2168 	 * Also set the corresponding bits in the returned attribute bitmap.
2169 	 */
2170 	if ((xoap = xva_getxoptattr(xvap)) != NULL && zfsvfs->z_use_fuids) {
2171 		if (XVA_ISSET_REQ(xvap, XAT_ARCHIVE)) {
2172 			xoap->xoa_archive =
2173 			    ((pzp->zp_flags & ZFS_ARCHIVE) != 0);
2174 			XVA_SET_RTN(xvap, XAT_ARCHIVE);
2175 		}
2176 
2177 		if (XVA_ISSET_REQ(xvap, XAT_READONLY)) {
2178 			xoap->xoa_readonly =
2179 			    ((pzp->zp_flags & ZFS_READONLY) != 0);
2180 			XVA_SET_RTN(xvap, XAT_READONLY);
2181 		}
2182 
2183 		if (XVA_ISSET_REQ(xvap, XAT_SYSTEM)) {
2184 			xoap->xoa_system =
2185 			    ((pzp->zp_flags & ZFS_SYSTEM) != 0);
2186 			XVA_SET_RTN(xvap, XAT_SYSTEM);
2187 		}
2188 
2189 		if (XVA_ISSET_REQ(xvap, XAT_HIDDEN)) {
2190 			xoap->xoa_hidden =
2191 			    ((pzp->zp_flags & ZFS_HIDDEN) != 0);
2192 			XVA_SET_RTN(xvap, XAT_HIDDEN);
2193 		}
2194 
2195 		if (XVA_ISSET_REQ(xvap, XAT_NOUNLINK)) {
2196 			xoap->xoa_nounlink =
2197 			    ((pzp->zp_flags & ZFS_NOUNLINK) != 0);
2198 			XVA_SET_RTN(xvap, XAT_NOUNLINK);
2199 		}
2200 
2201 		if (XVA_ISSET_REQ(xvap, XAT_IMMUTABLE)) {
2202 			xoap->xoa_immutable =
2203 			    ((pzp->zp_flags & ZFS_IMMUTABLE) != 0);
2204 			XVA_SET_RTN(xvap, XAT_IMMUTABLE);
2205 		}
2206 
2207 		if (XVA_ISSET_REQ(xvap, XAT_APPENDONLY)) {
2208 			xoap->xoa_appendonly =
2209 			    ((pzp->zp_flags & ZFS_APPENDONLY) != 0);
2210 			XVA_SET_RTN(xvap, XAT_APPENDONLY);
2211 		}
2212 
2213 		if (XVA_ISSET_REQ(xvap, XAT_NODUMP)) {
2214 			xoap->xoa_nodump =
2215 			    ((pzp->zp_flags & ZFS_NODUMP) != 0);
2216 			XVA_SET_RTN(xvap, XAT_NODUMP);
2217 		}
2218 
2219 		if (XVA_ISSET_REQ(xvap, XAT_OPAQUE)) {
2220 			xoap->xoa_opaque =
2221 			    ((pzp->zp_flags & ZFS_OPAQUE) != 0);
2222 			XVA_SET_RTN(xvap, XAT_OPAQUE);
2223 		}
2224 
2225 		if (XVA_ISSET_REQ(xvap, XAT_AV_QUARANTINED)) {
2226 			xoap->xoa_av_quarantined =
2227 			    ((pzp->zp_flags & ZFS_AV_QUARANTINED) != 0);
2228 			XVA_SET_RTN(xvap, XAT_AV_QUARANTINED);
2229 		}
2230 
2231 		if (XVA_ISSET_REQ(xvap, XAT_AV_MODIFIED)) {
2232 			xoap->xoa_av_modified =
2233 			    ((pzp->zp_flags & ZFS_AV_MODIFIED) != 0);
2234 			XVA_SET_RTN(xvap, XAT_AV_MODIFIED);
2235 		}
2236 
2237 		if (XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP) &&
2238 		    vp->v_type == VREG &&
2239 		    (pzp->zp_flags & ZFS_BONUS_SCANSTAMP)) {
2240 			size_t len;
2241 			dmu_object_info_t doi;
2242 
2243 			/*
2244 			 * Only VREG files have anti-virus scanstamps, so we
2245 			 * won't conflict with symlinks in the bonus buffer.
2246 			 */
2247 			dmu_object_info_from_db(zp->z_dbuf, &doi);
2248 			len = sizeof (xoap->xoa_av_scanstamp) +
2249 			    sizeof (znode_phys_t);
2250 			if (len <= doi.doi_bonus_size) {
2251 				/*
2252 				 * pzp points to the start of the
2253 				 * znode_phys_t. pzp + 1 points to the
2254 				 * first byte after the znode_phys_t.
2255 				 */
2256 				(void) memcpy(xoap->xoa_av_scanstamp,
2257 				    pzp + 1,
2258 				    sizeof (xoap->xoa_av_scanstamp));
2259 				XVA_SET_RTN(xvap, XAT_AV_SCANSTAMP);
2260 			}
2261 		}
2262 
2263 		if (XVA_ISSET_REQ(xvap, XAT_CREATETIME)) {
2264 			ZFS_TIME_DECODE(&xoap->xoa_createtime, pzp->zp_crtime);
2265 			XVA_SET_RTN(xvap, XAT_CREATETIME);
2266 		}
2267 	}
2268 
2269 	ZFS_TIME_DECODE(&vap->va_atime, pzp->zp_atime);
2270 	ZFS_TIME_DECODE(&vap->va_mtime, pzp->zp_mtime);
2271 	ZFS_TIME_DECODE(&vap->va_ctime, pzp->zp_ctime);
2272 
2273 	mutex_exit(&zp->z_lock);
2274 
2275 	dmu_object_size_from_db(zp->z_dbuf, &vap->va_blksize, &vap->va_nblocks);
2276 
2277 	if (zp->z_blksz == 0) {
2278 		/*
2279 		 * Block size hasn't been set; suggest maximal I/O transfers.
2280 		 */
2281 		vap->va_blksize = zfsvfs->z_max_blksz;
2282 	}
2283 
2284 	ZFS_EXIT(zfsvfs);
2285 	return (0);
2286 }
2287 
2288 /*
2289  * Set the file attributes to the values contained in the
2290  * vattr structure.
2291  *
2292  *	IN:	vp	- vnode of file to be modified.
2293  *		vap	- new attribute values.
2294  *			  If AT_XVATTR set, then optional attrs are being set
2295  *		flags	- ATTR_UTIME set if non-default time values provided.
2296  *			- ATTR_NOACLCHECK (CIFS context only).
2297  *		cr	- credentials of caller.
2298  *		ct	- caller context
2299  *
2300  *	RETURN:	0 if success
2301  *		error code if failure
2302  *
2303  * Timestamps:
2304  *	vp - ctime updated, mtime updated if size changed.
2305  */
2306 /* ARGSUSED */
2307 static int
2308 zfs_setattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
2309 	caller_context_t *ct)
2310 {
2311 	znode_t		*zp = VTOZ(vp);
2312 	znode_phys_t	*pzp;
2313 	zfsvfs_t	*zfsvfs = zp->z_zfsvfs;
2314 	zilog_t		*zilog;
2315 	dmu_tx_t	*tx;
2316 	vattr_t		oldva;
2317 	uint_t		mask = vap->va_mask;
2318 	uint_t		saved_mask;
2319 	int		trim_mask = 0;
2320 	uint64_t	new_mode;
2321 	znode_t		*attrzp;
2322 	int		need_policy = FALSE;
2323 	int		err;
2324 	zfs_fuid_info_t *fuidp = NULL;
2325 	xvattr_t *xvap = (xvattr_t *)vap;	/* vap may be an xvattr_t * */
2326 	xoptattr_t	*xoap;
2327 	boolean_t skipaclchk = (flags & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE;
2328 
2329 	if (mask == 0)
2330 		return (0);
2331 
2332 	if (mask & AT_NOSET)
2333 		return (EINVAL);
2334 
2335 	ZFS_ENTER(zfsvfs);
2336 	ZFS_VERIFY_ZP(zp);
2337 
2338 	pzp = zp->z_phys;
2339 	zilog = zfsvfs->z_log;
2340 
2341 	/*
2342 	 * Make sure that if we have ephemeral uid/gid or xvattr specified
2343 	 * that file system is at proper version level
2344 	 */
2345 
2346 	if (zfsvfs->z_use_fuids == B_FALSE &&
2347 	    (((mask & AT_UID) && IS_EPHEMERAL(vap->va_uid)) ||
2348 	    ((mask & AT_GID) && IS_EPHEMERAL(vap->va_gid)) ||
2349 	    (mask & AT_XVATTR))) {
2350 		ZFS_EXIT(zfsvfs);
2351 		return (EINVAL);
2352 	}
2353 
2354 	if (mask & AT_SIZE && vp->v_type == VDIR) {
2355 		ZFS_EXIT(zfsvfs);
2356 		return (EISDIR);
2357 	}
2358 
2359 	if (mask & AT_SIZE && vp->v_type != VREG && vp->v_type != VFIFO) {
2360 		ZFS_EXIT(zfsvfs);
2361 		return (EINVAL);
2362 	}
2363 
2364 	/*
2365 	 * If this is an xvattr_t, then get a pointer to the structure of
2366 	 * optional attributes.  If this is NULL, then we have a vattr_t.
2367 	 */
2368 	xoap = xva_getxoptattr(xvap);
2369 
2370 	/*
2371 	 * Immutable files can only alter immutable bit and atime
2372 	 */
2373 	if ((pzp->zp_flags & ZFS_IMMUTABLE) &&
2374 	    ((mask & (AT_SIZE|AT_UID|AT_GID|AT_MTIME|AT_MODE)) ||
2375 	    ((mask & AT_XVATTR) && XVA_ISSET_REQ(xvap, XAT_CREATETIME)))) {
2376 		ZFS_EXIT(zfsvfs);
2377 		return (EPERM);
2378 	}
2379 
2380 	if ((mask & AT_SIZE) && (pzp->zp_flags & ZFS_READONLY)) {
2381 		ZFS_EXIT(zfsvfs);
2382 		return (EPERM);
2383 	}
2384 
2385 top:
2386 	attrzp = NULL;
2387 
2388 	if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) {
2389 		ZFS_EXIT(zfsvfs);
2390 		return (EROFS);
2391 	}
2392 
2393 	/*
2394 	 * First validate permissions
2395 	 */
2396 
2397 	if (mask & AT_SIZE) {
2398 		err = zfs_zaccess(zp, ACE_WRITE_DATA, 0, skipaclchk, cr);
2399 		if (err) {
2400 			ZFS_EXIT(zfsvfs);
2401 			return (err);
2402 		}
2403 		/*
2404 		 * XXX - Note, we are not providing any open
2405 		 * mode flags here (like FNDELAY), so we may
2406 		 * block if there are locks present... this
2407 		 * should be addressed in openat().
2408 		 */
2409 		do {
2410 			err = zfs_freesp(zp, vap->va_size, 0, 0, FALSE);
2411 			/* NB: we already did dmu_tx_wait() if necessary */
2412 		} while (err == ERESTART && zfsvfs->z_assign == TXG_NOWAIT);
2413 		if (err) {
2414 			ZFS_EXIT(zfsvfs);
2415 			return (err);
2416 		}
2417 	}
2418 
2419 	if (mask & (AT_ATIME|AT_MTIME) ||
2420 	    ((mask & AT_XVATTR) && (XVA_ISSET_REQ(xvap, XAT_HIDDEN) ||
2421 	    XVA_ISSET_REQ(xvap, XAT_READONLY) ||
2422 	    XVA_ISSET_REQ(xvap, XAT_ARCHIVE) ||
2423 	    XVA_ISSET_REQ(xvap, XAT_CREATETIME) ||
2424 	    XVA_ISSET_REQ(xvap, XAT_SYSTEM))))
2425 		need_policy = zfs_zaccess(zp, ACE_WRITE_ATTRIBUTES, 0,
2426 		    skipaclchk, cr);
2427 
2428 	if (mask & (AT_UID|AT_GID)) {
2429 		int	idmask = (mask & (AT_UID|AT_GID));
2430 		int	take_owner;
2431 		int	take_group;
2432 
2433 		/*
2434 		 * NOTE: even if a new mode is being set,
2435 		 * we may clear S_ISUID/S_ISGID bits.
2436 		 */
2437 
2438 		if (!(mask & AT_MODE))
2439 			vap->va_mode = pzp->zp_mode;
2440 
2441 		/*
2442 		 * Take ownership or chgrp to group we are a member of
2443 		 */
2444 
2445 		take_owner = (mask & AT_UID) && (vap->va_uid == crgetuid(cr));
2446 		take_group = (mask & AT_GID) &&
2447 		    zfs_groupmember(zfsvfs, vap->va_gid, cr);
2448 
2449 		/*
2450 		 * If both AT_UID and AT_GID are set then take_owner and
2451 		 * take_group must both be set in order to allow taking
2452 		 * ownership.
2453 		 *
2454 		 * Otherwise, send the check through secpolicy_vnode_setattr()
2455 		 *
2456 		 */
2457 
2458 		if (((idmask == (AT_UID|AT_GID)) && take_owner && take_group) ||
2459 		    ((idmask == AT_UID) && take_owner) ||
2460 		    ((idmask == AT_GID) && take_group)) {
2461 			if (zfs_zaccess(zp, ACE_WRITE_OWNER, 0,
2462 			    skipaclchk, cr) == 0) {
2463 				/*
2464 				 * Remove setuid/setgid for non-privileged users
2465 				 */
2466 				secpolicy_setid_clear(vap, cr);
2467 				trim_mask = (mask & (AT_UID|AT_GID));
2468 			} else {
2469 				need_policy =  TRUE;
2470 			}
2471 		} else {
2472 			need_policy =  TRUE;
2473 		}
2474 	}
2475 
2476 	mutex_enter(&zp->z_lock);
2477 	oldva.va_mode = pzp->zp_mode;
2478 	zfs_fuid_map_ids(zp, &oldva.va_uid, &oldva.va_gid);
2479 	if (mask & AT_XVATTR) {
2480 		if ((need_policy == FALSE) &&
2481 		    (XVA_ISSET_REQ(xvap, XAT_APPENDONLY) &&
2482 		    xoap->xoa_appendonly !=
2483 		    ((pzp->zp_flags & ZFS_APPENDONLY) != 0)) ||
2484 		    (XVA_ISSET_REQ(xvap, XAT_NOUNLINK) &&
2485 		    xoap->xoa_nounlink !=
2486 		    ((pzp->zp_flags & ZFS_NOUNLINK) != 0)) ||
2487 		    (XVA_ISSET_REQ(xvap, XAT_IMMUTABLE) &&
2488 		    xoap->xoa_immutable !=
2489 		    ((pzp->zp_flags & ZFS_IMMUTABLE) != 0)) ||
2490 		    (XVA_ISSET_REQ(xvap, XAT_NODUMP) &&
2491 		    xoap->xoa_nodump !=
2492 		    ((pzp->zp_flags & ZFS_NODUMP) != 0)) ||
2493 		    (XVA_ISSET_REQ(xvap, XAT_AV_MODIFIED) &&
2494 		    xoap->xoa_av_modified !=
2495 		    ((pzp->zp_flags & ZFS_AV_MODIFIED) != 0)) ||
2496 		    (XVA_ISSET_REQ(xvap, XAT_AV_QUARANTINED) &&
2497 		    xoap->xoa_av_quarantined !=
2498 		    ((pzp->zp_flags & ZFS_AV_QUARANTINED) != 0)) ||
2499 		    (XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP)) ||
2500 		    (XVA_ISSET_REQ(xvap, XAT_OPAQUE))) {
2501 			need_policy = TRUE;
2502 		}
2503 	}
2504 
2505 	mutex_exit(&zp->z_lock);
2506 
2507 	if (mask & AT_MODE) {
2508 		if (zfs_zaccess(zp, ACE_WRITE_ACL, 0, skipaclchk, cr) == 0) {
2509 			err = secpolicy_setid_setsticky_clear(vp, vap,
2510 			    &oldva, cr);
2511 			if (err) {
2512 				ZFS_EXIT(zfsvfs);
2513 				return (err);
2514 			}
2515 			trim_mask |= AT_MODE;
2516 		} else {
2517 			need_policy = TRUE;
2518 		}
2519 	}
2520 
2521 	if (need_policy) {
2522 		/*
2523 		 * If trim_mask is set then take ownership
2524 		 * has been granted or write_acl is present and user
2525 		 * has the ability to modify mode.  In that case remove
2526 		 * UID|GID and or MODE from mask so that
2527 		 * secpolicy_vnode_setattr() doesn't revoke it.
2528 		 */
2529 
2530 		if (trim_mask) {
2531 			saved_mask = vap->va_mask;
2532 			vap->va_mask &= ~trim_mask;
2533 		}
2534 		err = secpolicy_vnode_setattr(cr, vp, vap, &oldva, flags,
2535 		    (int (*)(void *, int, cred_t *))zfs_zaccess_unix, zp);
2536 		if (err) {
2537 			ZFS_EXIT(zfsvfs);
2538 			return (err);
2539 		}
2540 
2541 		if (trim_mask)
2542 			vap->va_mask |= saved_mask;
2543 	}
2544 
2545 	/*
2546 	 * secpolicy_vnode_setattr, or take ownership may have
2547 	 * changed va_mask
2548 	 */
2549 	mask = vap->va_mask;
2550 
2551 	tx = dmu_tx_create(zfsvfs->z_os);
2552 	dmu_tx_hold_bonus(tx, zp->z_id);
2553 	if (zfsvfs->z_fuid_obj == 0) {
2554 		dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT);
2555 		dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0,
2556 		    SPA_MAXBLOCKSIZE);
2557 		dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, FALSE, NULL);
2558 	} else {
2559 		dmu_tx_hold_bonus(tx, zfsvfs->z_fuid_obj);
2560 		dmu_tx_hold_write(tx, zfsvfs->z_fuid_obj, 0,
2561 		    SPA_MAXBLOCKSIZE);
2562 	}
2563 
2564 	if (mask & AT_MODE) {
2565 		uint64_t pmode = pzp->zp_mode;
2566 
2567 		new_mode = (pmode & S_IFMT) | (vap->va_mode & ~S_IFMT);
2568 
2569 		if (pzp->zp_acl.z_acl_extern_obj) {
2570 			/* Are we upgrading ACL from old V0 format to new V1 */
2571 			if (zfsvfs->z_version <= ZPL_VERSION_FUID &&
2572 			    pzp->zp_acl.z_acl_version ==
2573 			    ZFS_ACL_VERSION_INITIAL) {
2574 				dmu_tx_hold_free(tx,
2575 				    pzp->zp_acl.z_acl_extern_obj, 0,
2576 				    DMU_OBJECT_END);
2577 				dmu_tx_hold_write(tx, DMU_NEW_OBJECT,
2578 				    0, sizeof (zfs_object_ace_t) * 2048 + 6);
2579 			} else {
2580 				dmu_tx_hold_write(tx,
2581 				    pzp->zp_acl.z_acl_extern_obj, 0,
2582 				    SPA_MAXBLOCKSIZE);
2583 			}
2584 		} else {
2585 			dmu_tx_hold_write(tx, DMU_NEW_OBJECT,
2586 			    0, sizeof (zfs_object_ace_t) * 2048 + 6);
2587 		}
2588 	}
2589 
2590 	if ((mask & (AT_UID | AT_GID)) && pzp->zp_xattr != 0) {
2591 		err = zfs_zget(zp->z_zfsvfs, pzp->zp_xattr, &attrzp);
2592 		if (err) {
2593 			dmu_tx_abort(tx);
2594 			ZFS_EXIT(zfsvfs);
2595 			return (err);
2596 		}
2597 		dmu_tx_hold_bonus(tx, attrzp->z_id);
2598 	}
2599 
2600 	err = dmu_tx_assign(tx, zfsvfs->z_assign);
2601 	if (err) {
2602 		if (attrzp)
2603 			VN_RELE(ZTOV(attrzp));
2604 		if (err == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) {
2605 			dmu_tx_wait(tx);
2606 			dmu_tx_abort(tx);
2607 			goto top;
2608 		}
2609 		dmu_tx_abort(tx);
2610 		ZFS_EXIT(zfsvfs);
2611 		return (err);
2612 	}
2613 
2614 	dmu_buf_will_dirty(zp->z_dbuf, tx);
2615 
2616 	/*
2617 	 * Set each attribute requested.
2618 	 * We group settings according to the locks they need to acquire.
2619 	 *
2620 	 * Note: you cannot set ctime directly, although it will be
2621 	 * updated as a side-effect of calling this function.
2622 	 */
2623 
2624 	mutex_enter(&zp->z_lock);
2625 
2626 	if (mask & AT_MODE) {
2627 		err = zfs_acl_chmod_setattr(zp, new_mode, tx);
2628 		ASSERT3U(err, ==, 0);
2629 	}
2630 
2631 	if (attrzp)
2632 		mutex_enter(&attrzp->z_lock);
2633 
2634 	if (mask & AT_UID) {
2635 		pzp->zp_uid = zfs_fuid_create(zfsvfs,
2636 		    vap->va_uid, ZFS_OWNER, tx, &fuidp);
2637 		if (attrzp) {
2638 			attrzp->z_phys->zp_uid = zfs_fuid_create(zfsvfs,
2639 			    vap->va_uid,  ZFS_OWNER, tx, &fuidp);
2640 		}
2641 	}
2642 
2643 	if (mask & AT_GID) {
2644 		pzp->zp_gid = zfs_fuid_create(zfsvfs, vap->va_gid,
2645 		    ZFS_GROUP, tx, &fuidp);
2646 		if (attrzp)
2647 			attrzp->z_phys->zp_gid = zfs_fuid_create(zfsvfs,
2648 			    vap->va_gid, ZFS_GROUP, tx, &fuidp);
2649 	}
2650 
2651 	if (attrzp)
2652 		mutex_exit(&attrzp->z_lock);
2653 
2654 	if (mask & AT_ATIME)
2655 		ZFS_TIME_ENCODE(&vap->va_atime, pzp->zp_atime);
2656 
2657 	if (mask & AT_MTIME)
2658 		ZFS_TIME_ENCODE(&vap->va_mtime, pzp->zp_mtime);
2659 
2660 	if (mask & AT_SIZE)
2661 		zfs_time_stamper_locked(zp, CONTENT_MODIFIED, tx);
2662 	else if (mask != 0)
2663 		zfs_time_stamper_locked(zp, STATE_CHANGED, tx);
2664 	/*
2665 	 * Do this after setting timestamps to prevent timestamp
2666 	 * update from toggling bit
2667 	 */
2668 
2669 	if (xoap && (mask & AT_XVATTR)) {
2670 		if (XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP)) {
2671 			size_t len;
2672 			dmu_object_info_t doi;
2673 
2674 			ASSERT(vp->v_type == VREG);
2675 
2676 			/* Grow the bonus buffer if necessary. */
2677 			dmu_object_info_from_db(zp->z_dbuf, &doi);
2678 			len = sizeof (xoap->xoa_av_scanstamp) +
2679 			    sizeof (znode_phys_t);
2680 			if (len > doi.doi_bonus_size)
2681 				VERIFY(dmu_set_bonus(zp->z_dbuf, len, tx) == 0);
2682 		}
2683 		zfs_xvattr_set(zp, xvap);
2684 	}
2685 
2686 	if (mask != 0)
2687 		zfs_log_setattr(zilog, tx, TX_SETATTR, zp, vap, mask, fuidp);
2688 
2689 	if (fuidp)
2690 		zfs_fuid_info_free(fuidp);
2691 	mutex_exit(&zp->z_lock);
2692 
2693 	if (attrzp)
2694 		VN_RELE(ZTOV(attrzp));
2695 
2696 	dmu_tx_commit(tx);
2697 
2698 	ZFS_EXIT(zfsvfs);
2699 	return (err);
2700 }
2701 
2702 typedef struct zfs_zlock {
2703 	krwlock_t	*zl_rwlock;	/* lock we acquired */
2704 	znode_t		*zl_znode;	/* znode we held */
2705 	struct zfs_zlock *zl_next;	/* next in list */
2706 } zfs_zlock_t;
2707 
2708 /*
2709  * Drop locks and release vnodes that were held by zfs_rename_lock().
2710  */
2711 static void
2712 zfs_rename_unlock(zfs_zlock_t **zlpp)
2713 {
2714 	zfs_zlock_t *zl;
2715 
2716 	while ((zl = *zlpp) != NULL) {
2717 		if (zl->zl_znode != NULL)
2718 			VN_RELE(ZTOV(zl->zl_znode));
2719 		rw_exit(zl->zl_rwlock);
2720 		*zlpp = zl->zl_next;
2721 		kmem_free(zl, sizeof (*zl));
2722 	}
2723 }
2724 
2725 /*
2726  * Search back through the directory tree, using the ".." entries.
2727  * Lock each directory in the chain to prevent concurrent renames.
2728  * Fail any attempt to move a directory into one of its own descendants.
2729  * XXX - z_parent_lock can overlap with map or grow locks
2730  */
2731 static int
2732 zfs_rename_lock(znode_t *szp, znode_t *tdzp, znode_t *sdzp, zfs_zlock_t **zlpp)
2733 {
2734 	zfs_zlock_t	*zl;
2735 	znode_t		*zp = tdzp;
2736 	uint64_t	rootid = zp->z_zfsvfs->z_root;
2737 	uint64_t	*oidp = &zp->z_id;
2738 	krwlock_t	*rwlp = &szp->z_parent_lock;
2739 	krw_t		rw = RW_WRITER;
2740 
2741 	/*
2742 	 * First pass write-locks szp and compares to zp->z_id.
2743 	 * Later passes read-lock zp and compare to zp->z_parent.
2744 	 */
2745 	do {
2746 		if (!rw_tryenter(rwlp, rw)) {
2747 			/*
2748 			 * Another thread is renaming in this path.
2749 			 * Note that if we are a WRITER, we don't have any
2750 			 * parent_locks held yet.
2751 			 */
2752 			if (rw == RW_READER && zp->z_id > szp->z_id) {
2753 				/*
2754 				 * Drop our locks and restart
2755 				 */
2756 				zfs_rename_unlock(&zl);
2757 				*zlpp = NULL;
2758 				zp = tdzp;
2759 				oidp = &zp->z_id;
2760 				rwlp = &szp->z_parent_lock;
2761 				rw = RW_WRITER;
2762 				continue;
2763 			} else {
2764 				/*
2765 				 * Wait for other thread to drop its locks
2766 				 */
2767 				rw_enter(rwlp, rw);
2768 			}
2769 		}
2770 
2771 		zl = kmem_alloc(sizeof (*zl), KM_SLEEP);
2772 		zl->zl_rwlock = rwlp;
2773 		zl->zl_znode = NULL;
2774 		zl->zl_next = *zlpp;
2775 		*zlpp = zl;
2776 
2777 		if (*oidp == szp->z_id)		/* We're a descendant of szp */
2778 			return (EINVAL);
2779 
2780 		if (*oidp == rootid)		/* We've hit the top */
2781 			return (0);
2782 
2783 		if (rw == RW_READER) {		/* i.e. not the first pass */
2784 			int error = zfs_zget(zp->z_zfsvfs, *oidp, &zp);
2785 			if (error)
2786 				return (error);
2787 			zl->zl_znode = zp;
2788 		}
2789 		oidp = &zp->z_phys->zp_parent;
2790 		rwlp = &zp->z_parent_lock;
2791 		rw = RW_READER;
2792 
2793 	} while (zp->z_id != sdzp->z_id);
2794 
2795 	return (0);
2796 }
2797 
2798 /*
2799  * Move an entry from the provided source directory to the target
2800  * directory.  Change the entry name as indicated.
2801  *
2802  *	IN:	sdvp	- Source directory containing the "old entry".
2803  *		snm	- Old entry name.
2804  *		tdvp	- Target directory to contain the "new entry".
2805  *		tnm	- New entry name.
2806  *		cr	- credentials of caller.
2807  *		ct	- caller context
2808  *		flags	- case flags
2809  *
2810  *	RETURN:	0 if success
2811  *		error code if failure
2812  *
2813  * Timestamps:
2814  *	sdvp,tdvp - ctime|mtime updated
2815  */
2816 /*ARGSUSED*/
2817 static int
2818 zfs_rename(vnode_t *sdvp, char *snm, vnode_t *tdvp, char *tnm, cred_t *cr,
2819     caller_context_t *ct, int flags)
2820 {
2821 	znode_t		*tdzp, *szp, *tzp;
2822 	znode_t		*sdzp = VTOZ(sdvp);
2823 	zfsvfs_t	*zfsvfs = sdzp->z_zfsvfs;
2824 	zilog_t		*zilog;
2825 	vnode_t		*realvp;
2826 	zfs_dirlock_t	*sdl, *tdl;
2827 	dmu_tx_t	*tx;
2828 	zfs_zlock_t	*zl;
2829 	int		cmp, serr, terr;
2830 	int		error = 0;
2831 	int		zflg = 0;
2832 
2833 	ZFS_ENTER(zfsvfs);
2834 	ZFS_VERIFY_ZP(sdzp);
2835 	zilog = zfsvfs->z_log;
2836 
2837 	/*
2838 	 * Make sure we have the real vp for the target directory.
2839 	 */
2840 	if (VOP_REALVP(tdvp, &realvp, ct) == 0)
2841 		tdvp = realvp;
2842 
2843 	if (tdvp->v_vfsp != sdvp->v_vfsp) {
2844 		ZFS_EXIT(zfsvfs);
2845 		return (EXDEV);
2846 	}
2847 
2848 	tdzp = VTOZ(tdvp);
2849 	ZFS_VERIFY_ZP(tdzp);
2850 	if (zfsvfs->z_utf8 && u8_validate(tnm,
2851 	    strlen(tnm), NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
2852 		ZFS_EXIT(zfsvfs);
2853 		return (EILSEQ);
2854 	}
2855 
2856 	if (flags & FIGNORECASE)
2857 		zflg |= ZCILOOK;
2858 
2859 top:
2860 	szp = NULL;
2861 	tzp = NULL;
2862 	zl = NULL;
2863 
2864 	/*
2865 	 * This is to prevent the creation of links into attribute space
2866 	 * by renaming a linked file into/outof an attribute directory.
2867 	 * See the comment in zfs_link() for why this is considered bad.
2868 	 */
2869 	if ((tdzp->z_phys->zp_flags & ZFS_XATTR) !=
2870 	    (sdzp->z_phys->zp_flags & ZFS_XATTR)) {
2871 		ZFS_EXIT(zfsvfs);
2872 		return (EINVAL);
2873 	}
2874 
2875 	/*
2876 	 * Lock source and target directory entries.  To prevent deadlock,
2877 	 * a lock ordering must be defined.  We lock the directory with
2878 	 * the smallest object id first, or if it's a tie, the one with
2879 	 * the lexically first name.
2880 	 */
2881 	if (sdzp->z_id < tdzp->z_id) {
2882 		cmp = -1;
2883 	} else if (sdzp->z_id > tdzp->z_id) {
2884 		cmp = 1;
2885 	} else {
2886 		/*
2887 		 * First compare the two name arguments without
2888 		 * considering any case folding.
2889 		 */
2890 		int nofold = (zfsvfs->z_norm & ~U8_TEXTPREP_TOUPPER);
2891 
2892 		cmp = u8_strcmp(snm, tnm, 0, nofold, U8_UNICODE_LATEST, &error);
2893 		ASSERT(error == 0 || !zfsvfs->z_utf8);
2894 		if (cmp == 0) {
2895 			/*
2896 			 * POSIX: "If the old argument and the new argument
2897 			 * both refer to links to the same existing file,
2898 			 * the rename() function shall return successfully
2899 			 * and perform no other action."
2900 			 */
2901 			ZFS_EXIT(zfsvfs);
2902 			return (0);
2903 		}
2904 		/*
2905 		 * If the file system is case-folding, then we may
2906 		 * have some more checking to do.  A case-folding file
2907 		 * system is either supporting mixed case sensitivity
2908 		 * access or is completely case-insensitive.  Note
2909 		 * that the file system is always case preserving.
2910 		 *
2911 		 * In mixed sensitivity mode case sensitive behavior
2912 		 * is the default.  FIGNORECASE must be used to
2913 		 * explicitly request case insensitive behavior.
2914 		 *
2915 		 * If the source and target names provided differ only
2916 		 * by case (e.g., a request to rename 'tim' to 'Tim'),
2917 		 * we will treat this as a special case in the
2918 		 * case-insensitive mode: as long as the source name
2919 		 * is an exact match, we will allow this to proceed as
2920 		 * a name-change request.
2921 		 */
2922 		if ((zfsvfs->z_case == ZFS_CASE_INSENSITIVE ||
2923 		    (zfsvfs->z_case == ZFS_CASE_MIXED &&
2924 		    flags & FIGNORECASE)) &&
2925 		    u8_strcmp(snm, tnm, 0, zfsvfs->z_norm, U8_UNICODE_LATEST,
2926 		    &error) == 0) {
2927 			/*
2928 			 * case preserving rename request, require exact
2929 			 * name matches
2930 			 */
2931 			zflg |= ZCIEXACT;
2932 			zflg &= ~ZCILOOK;
2933 		}
2934 	}
2935 
2936 	if (cmp < 0) {
2937 		serr = zfs_dirent_lock(&sdl, sdzp, snm, &szp,
2938 		    ZEXISTS | zflg, NULL, NULL);
2939 		terr = zfs_dirent_lock(&tdl,
2940 		    tdzp, tnm, &tzp, ZRENAMING | zflg, NULL, NULL);
2941 	} else {
2942 		terr = zfs_dirent_lock(&tdl,
2943 		    tdzp, tnm, &tzp, zflg, NULL, NULL);
2944 		serr = zfs_dirent_lock(&sdl,
2945 		    sdzp, snm, &szp, ZEXISTS | ZRENAMING | zflg,
2946 		    NULL, NULL);
2947 	}
2948 
2949 	if (serr) {
2950 		/*
2951 		 * Source entry invalid or not there.
2952 		 */
2953 		if (!terr) {
2954 			zfs_dirent_unlock(tdl);
2955 			if (tzp)
2956 				VN_RELE(ZTOV(tzp));
2957 		}
2958 		if (strcmp(snm, "..") == 0)
2959 			serr = EINVAL;
2960 		ZFS_EXIT(zfsvfs);
2961 		return (serr);
2962 	}
2963 	if (terr) {
2964 		zfs_dirent_unlock(sdl);
2965 		VN_RELE(ZTOV(szp));
2966 		if (strcmp(tnm, "..") == 0)
2967 			terr = EINVAL;
2968 		ZFS_EXIT(zfsvfs);
2969 		return (terr);
2970 	}
2971 
2972 	/*
2973 	 * Must have write access at the source to remove the old entry
2974 	 * and write access at the target to create the new entry.
2975 	 * Note that if target and source are the same, this can be
2976 	 * done in a single check.
2977 	 */
2978 
2979 	if (error = zfs_zaccess_rename(sdzp, szp, tdzp, tzp, cr))
2980 		goto out;
2981 
2982 	if (ZTOV(szp)->v_type == VDIR) {
2983 		/*
2984 		 * Check to make sure rename is valid.
2985 		 * Can't do a move like this: /usr/a/b to /usr/a/b/c/d
2986 		 */
2987 		if (error = zfs_rename_lock(szp, tdzp, sdzp, &zl))
2988 			goto out;
2989 	}
2990 
2991 	/*
2992 	 * Does target exist?
2993 	 */
2994 	if (tzp) {
2995 		/*
2996 		 * Source and target must be the same type.
2997 		 */
2998 		if (ZTOV(szp)->v_type == VDIR) {
2999 			if (ZTOV(tzp)->v_type != VDIR) {
3000 				error = ENOTDIR;
3001 				goto out;
3002 			}
3003 		} else {
3004 			if (ZTOV(tzp)->v_type == VDIR) {
3005 				error = EISDIR;
3006 				goto out;
3007 			}
3008 		}
3009 		/*
3010 		 * POSIX dictates that when the source and target
3011 		 * entries refer to the same file object, rename
3012 		 * must do nothing and exit without error.
3013 		 */
3014 		if (szp->z_id == tzp->z_id) {
3015 			error = 0;
3016 			goto out;
3017 		}
3018 	}
3019 
3020 	vnevent_rename_src(ZTOV(szp), sdvp, snm, ct);
3021 	if (tzp)
3022 		vnevent_rename_dest(ZTOV(tzp), tdvp, tnm, ct);
3023 
3024 	/*
3025 	 * notify the target directory if it is not the same
3026 	 * as source directory.
3027 	 */
3028 	if (tdvp != sdvp) {
3029 		vnevent_rename_dest_dir(tdvp, ct);
3030 	}
3031 
3032 	tx = dmu_tx_create(zfsvfs->z_os);
3033 	dmu_tx_hold_bonus(tx, szp->z_id);	/* nlink changes */
3034 	dmu_tx_hold_bonus(tx, sdzp->z_id);	/* nlink changes */
3035 	dmu_tx_hold_zap(tx, sdzp->z_id, FALSE, snm);
3036 	dmu_tx_hold_zap(tx, tdzp->z_id, TRUE, tnm);
3037 	if (sdzp != tdzp)
3038 		dmu_tx_hold_bonus(tx, tdzp->z_id);	/* nlink changes */
3039 	if (tzp)
3040 		dmu_tx_hold_bonus(tx, tzp->z_id);	/* parent changes */
3041 	dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
3042 	error = dmu_tx_assign(tx, zfsvfs->z_assign);
3043 	if (error) {
3044 		if (zl != NULL)
3045 			zfs_rename_unlock(&zl);
3046 		zfs_dirent_unlock(sdl);
3047 		zfs_dirent_unlock(tdl);
3048 		VN_RELE(ZTOV(szp));
3049 		if (tzp)
3050 			VN_RELE(ZTOV(tzp));
3051 		if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) {
3052 			dmu_tx_wait(tx);
3053 			dmu_tx_abort(tx);
3054 			goto top;
3055 		}
3056 		dmu_tx_abort(tx);
3057 		ZFS_EXIT(zfsvfs);
3058 		return (error);
3059 	}
3060 
3061 	if (tzp)	/* Attempt to remove the existing target */
3062 		error = zfs_link_destroy(tdl, tzp, tx, zflg, NULL);
3063 
3064 	if (error == 0) {
3065 		error = zfs_link_create(tdl, szp, tx, ZRENAMING);
3066 		if (error == 0) {
3067 			szp->z_phys->zp_flags |= ZFS_AV_MODIFIED;
3068 
3069 			error = zfs_link_destroy(sdl, szp, tx, ZRENAMING, NULL);
3070 			ASSERT(error == 0);
3071 
3072 			zfs_log_rename(zilog, tx,
3073 			    TX_RENAME | (flags & FIGNORECASE ? TX_CI : 0),
3074 			    sdzp, sdl->dl_name, tdzp, tdl->dl_name, szp);
3075 		}
3076 	}
3077 
3078 	dmu_tx_commit(tx);
3079 out:
3080 	if (zl != NULL)
3081 		zfs_rename_unlock(&zl);
3082 
3083 	zfs_dirent_unlock(sdl);
3084 	zfs_dirent_unlock(tdl);
3085 
3086 	VN_RELE(ZTOV(szp));
3087 	if (tzp)
3088 		VN_RELE(ZTOV(tzp));
3089 
3090 	ZFS_EXIT(zfsvfs);
3091 	return (error);
3092 }
3093 
3094 /*
3095  * Insert the indicated symbolic reference entry into the directory.
3096  *
3097  *	IN:	dvp	- Directory to contain new symbolic link.
3098  *		link	- Name for new symlink entry.
3099  *		vap	- Attributes of new entry.
3100  *		target	- Target path of new symlink.
3101  *		cr	- credentials of caller.
3102  *		ct	- caller context
3103  *		flags	- case flags
3104  *
3105  *	RETURN:	0 if success
3106  *		error code if failure
3107  *
3108  * Timestamps:
3109  *	dvp - ctime|mtime updated
3110  */
3111 /*ARGSUSED*/
3112 static int
3113 zfs_symlink(vnode_t *dvp, char *name, vattr_t *vap, char *link, cred_t *cr,
3114     caller_context_t *ct, int flags)
3115 {
3116 	znode_t		*zp, *dzp = VTOZ(dvp);
3117 	zfs_dirlock_t	*dl;
3118 	dmu_tx_t	*tx;
3119 	zfsvfs_t	*zfsvfs = dzp->z_zfsvfs;
3120 	zilog_t		*zilog;
3121 	int		len = strlen(link);
3122 	int		error;
3123 	int		zflg = ZNEW;
3124 	zfs_fuid_info_t *fuidp = NULL;
3125 
3126 	ASSERT(vap->va_type == VLNK);
3127 
3128 	ZFS_ENTER(zfsvfs);
3129 	ZFS_VERIFY_ZP(dzp);
3130 	zilog = zfsvfs->z_log;
3131 
3132 	if (zfsvfs->z_utf8 && u8_validate(name, strlen(name),
3133 	    NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
3134 		ZFS_EXIT(zfsvfs);
3135 		return (EILSEQ);
3136 	}
3137 	if (flags & FIGNORECASE)
3138 		zflg |= ZCILOOK;
3139 top:
3140 	if (error = zfs_zaccess(dzp, ACE_ADD_FILE, 0, B_FALSE, cr)) {
3141 		ZFS_EXIT(zfsvfs);
3142 		return (error);
3143 	}
3144 
3145 	if (len > MAXPATHLEN) {
3146 		ZFS_EXIT(zfsvfs);
3147 		return (ENAMETOOLONG);
3148 	}
3149 
3150 	/*
3151 	 * Attempt to lock directory; fail if entry already exists.
3152 	 */
3153 	error = zfs_dirent_lock(&dl, dzp, name, &zp, zflg, NULL, NULL);
3154 	if (error) {
3155 		ZFS_EXIT(zfsvfs);
3156 		return (error);
3157 	}
3158 
3159 	tx = dmu_tx_create(zfsvfs->z_os);
3160 	dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, MAX(1, len));
3161 	dmu_tx_hold_bonus(tx, dzp->z_id);
3162 	dmu_tx_hold_zap(tx, dzp->z_id, TRUE, name);
3163 	if (dzp->z_phys->zp_flags & ZFS_INHERIT_ACE)
3164 		dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, SPA_MAXBLOCKSIZE);
3165 	if (zfsvfs->z_fuid_obj == 0) {
3166 		dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT);
3167 		dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0,
3168 		    SPA_MAXBLOCKSIZE);
3169 		dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, FALSE, NULL);
3170 	} else {
3171 		dmu_tx_hold_bonus(tx, zfsvfs->z_fuid_obj);
3172 		dmu_tx_hold_write(tx, zfsvfs->z_fuid_obj, 0,
3173 		    SPA_MAXBLOCKSIZE);
3174 	}
3175 	error = dmu_tx_assign(tx, zfsvfs->z_assign);
3176 	if (error) {
3177 		zfs_dirent_unlock(dl);
3178 		if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) {
3179 			dmu_tx_wait(tx);
3180 			dmu_tx_abort(tx);
3181 			goto top;
3182 		}
3183 		dmu_tx_abort(tx);
3184 		ZFS_EXIT(zfsvfs);
3185 		return (error);
3186 	}
3187 
3188 	dmu_buf_will_dirty(dzp->z_dbuf, tx);
3189 
3190 	/*
3191 	 * Create a new object for the symlink.
3192 	 * Put the link content into bonus buffer if it will fit;
3193 	 * otherwise, store it just like any other file data.
3194 	 */
3195 	if (sizeof (znode_phys_t) + len <= dmu_bonus_max()) {
3196 		zfs_mknode(dzp, vap, tx, cr, 0, &zp, len, NULL, &fuidp);
3197 		if (len != 0)
3198 			bcopy(link, zp->z_phys + 1, len);
3199 	} else {
3200 		dmu_buf_t *dbp;
3201 
3202 		zfs_mknode(dzp, vap, tx, cr, 0, &zp, 0, NULL, &fuidp);
3203 		/*
3204 		 * Nothing can access the znode yet so no locking needed
3205 		 * for growing the znode's blocksize.
3206 		 */
3207 		zfs_grow_blocksize(zp, len, tx);
3208 
3209 		VERIFY(0 == dmu_buf_hold(zfsvfs->z_os,
3210 		    zp->z_id, 0, FTAG, &dbp));
3211 		dmu_buf_will_dirty(dbp, tx);
3212 
3213 		ASSERT3U(len, <=, dbp->db_size);
3214 		bcopy(link, dbp->db_data, len);
3215 		dmu_buf_rele(dbp, FTAG);
3216 	}
3217 	zp->z_phys->zp_size = len;
3218 
3219 	/*
3220 	 * Insert the new object into the directory.
3221 	 */
3222 	(void) zfs_link_create(dl, zp, tx, ZNEW);
3223 out:
3224 	if (error == 0) {
3225 		uint64_t txtype = TX_SYMLINK;
3226 		if (flags & FIGNORECASE)
3227 			txtype |= TX_CI;
3228 		zfs_log_symlink(zilog, tx, txtype, dzp, zp, name, link);
3229 	}
3230 	if (fuidp)
3231 		zfs_fuid_info_free(fuidp);
3232 
3233 	dmu_tx_commit(tx);
3234 
3235 	zfs_dirent_unlock(dl);
3236 
3237 	VN_RELE(ZTOV(zp));
3238 
3239 	ZFS_EXIT(zfsvfs);
3240 	return (error);
3241 }
3242 
3243 /*
3244  * Return, in the buffer contained in the provided uio structure,
3245  * the symbolic path referred to by vp.
3246  *
3247  *	IN:	vp	- vnode of symbolic link.
3248  *		uoip	- structure to contain the link path.
3249  *		cr	- credentials of caller.
3250  *		ct	- caller context
3251  *
3252  *	OUT:	uio	- structure to contain the link path.
3253  *
3254  *	RETURN:	0 if success
3255  *		error code if failure
3256  *
3257  * Timestamps:
3258  *	vp - atime updated
3259  */
3260 /* ARGSUSED */
3261 static int
3262 zfs_readlink(vnode_t *vp, uio_t *uio, cred_t *cr, caller_context_t *ct)
3263 {
3264 	znode_t		*zp = VTOZ(vp);
3265 	zfsvfs_t	*zfsvfs = zp->z_zfsvfs;
3266 	size_t		bufsz;
3267 	int		error;
3268 
3269 	ZFS_ENTER(zfsvfs);
3270 	ZFS_VERIFY_ZP(zp);
3271 
3272 	bufsz = (size_t)zp->z_phys->zp_size;
3273 	if (bufsz + sizeof (znode_phys_t) <= zp->z_dbuf->db_size) {
3274 		error = uiomove(zp->z_phys + 1,
3275 		    MIN((size_t)bufsz, uio->uio_resid), UIO_READ, uio);
3276 	} else {
3277 		dmu_buf_t *dbp;
3278 		error = dmu_buf_hold(zfsvfs->z_os, zp->z_id, 0, FTAG, &dbp);
3279 		if (error) {
3280 			ZFS_EXIT(zfsvfs);
3281 			return (error);
3282 		}
3283 		error = uiomove(dbp->db_data,
3284 		    MIN((size_t)bufsz, uio->uio_resid), UIO_READ, uio);
3285 		dmu_buf_rele(dbp, FTAG);
3286 	}
3287 
3288 	ZFS_ACCESSTIME_STAMP(zfsvfs, zp);
3289 	ZFS_EXIT(zfsvfs);
3290 	return (error);
3291 }
3292 
3293 /*
3294  * Insert a new entry into directory tdvp referencing svp.
3295  *
3296  *	IN:	tdvp	- Directory to contain new entry.
3297  *		svp	- vnode of new entry.
3298  *		name	- name of new entry.
3299  *		cr	- credentials of caller.
3300  *		ct	- caller context
3301  *
3302  *	RETURN:	0 if success
3303  *		error code if failure
3304  *
3305  * Timestamps:
3306  *	tdvp - ctime|mtime updated
3307  *	 svp - ctime updated
3308  */
3309 /* ARGSUSED */
3310 static int
3311 zfs_link(vnode_t *tdvp, vnode_t *svp, char *name, cred_t *cr,
3312     caller_context_t *ct, int flags)
3313 {
3314 	znode_t		*dzp = VTOZ(tdvp);
3315 	znode_t		*tzp, *szp;
3316 	zfsvfs_t	*zfsvfs = dzp->z_zfsvfs;
3317 	zilog_t		*zilog;
3318 	zfs_dirlock_t	*dl;
3319 	dmu_tx_t	*tx;
3320 	vnode_t		*realvp;
3321 	int		error;
3322 	int		zf = ZNEW;
3323 	uid_t		owner;
3324 
3325 	ASSERT(tdvp->v_type == VDIR);
3326 
3327 	ZFS_ENTER(zfsvfs);
3328 	ZFS_VERIFY_ZP(dzp);
3329 	zilog = zfsvfs->z_log;
3330 
3331 	if (VOP_REALVP(svp, &realvp, ct) == 0)
3332 		svp = realvp;
3333 
3334 	if (svp->v_vfsp != tdvp->v_vfsp) {
3335 		ZFS_EXIT(zfsvfs);
3336 		return (EXDEV);
3337 	}
3338 	szp = VTOZ(svp);
3339 	ZFS_VERIFY_ZP(szp);
3340 
3341 	if (zfsvfs->z_utf8 && u8_validate(name,
3342 	    strlen(name), NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
3343 		ZFS_EXIT(zfsvfs);
3344 		return (EILSEQ);
3345 	}
3346 	if (flags & FIGNORECASE)
3347 		zf |= ZCILOOK;
3348 
3349 top:
3350 	/*
3351 	 * We do not support links between attributes and non-attributes
3352 	 * because of the potential security risk of creating links
3353 	 * into "normal" file space in order to circumvent restrictions
3354 	 * imposed in attribute space.
3355 	 */
3356 	if ((szp->z_phys->zp_flags & ZFS_XATTR) !=
3357 	    (dzp->z_phys->zp_flags & ZFS_XATTR)) {
3358 		ZFS_EXIT(zfsvfs);
3359 		return (EINVAL);
3360 	}
3361 
3362 	/*
3363 	 * POSIX dictates that we return EPERM here.
3364 	 * Better choices include ENOTSUP or EISDIR.
3365 	 */
3366 	if (svp->v_type == VDIR) {
3367 		ZFS_EXIT(zfsvfs);
3368 		return (EPERM);
3369 	}
3370 
3371 	zfs_fuid_map_id(zfsvfs, szp->z_phys->zp_uid, ZFS_OWNER, &owner);
3372 	if (owner != crgetuid(cr) &&
3373 	    secpolicy_basic_link(cr) != 0) {
3374 		ZFS_EXIT(zfsvfs);
3375 		return (EPERM);
3376 	}
3377 
3378 	if (error = zfs_zaccess(dzp, ACE_ADD_FILE, 0, B_FALSE, cr)) {
3379 		ZFS_EXIT(zfsvfs);
3380 		return (error);
3381 	}
3382 
3383 	/*
3384 	 * Attempt to lock directory; fail if entry already exists.
3385 	 */
3386 	error = zfs_dirent_lock(&dl, dzp, name, &tzp, zf, NULL, NULL);
3387 	if (error) {
3388 		ZFS_EXIT(zfsvfs);
3389 		return (error);
3390 	}
3391 
3392 	tx = dmu_tx_create(zfsvfs->z_os);
3393 	dmu_tx_hold_bonus(tx, szp->z_id);
3394 	dmu_tx_hold_zap(tx, dzp->z_id, TRUE, name);
3395 	error = dmu_tx_assign(tx, zfsvfs->z_assign);
3396 	if (error) {
3397 		zfs_dirent_unlock(dl);
3398 		if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) {
3399 			dmu_tx_wait(tx);
3400 			dmu_tx_abort(tx);
3401 			goto top;
3402 		}
3403 		dmu_tx_abort(tx);
3404 		ZFS_EXIT(zfsvfs);
3405 		return (error);
3406 	}
3407 
3408 	error = zfs_link_create(dl, szp, tx, 0);
3409 
3410 	if (error == 0) {
3411 		uint64_t txtype = TX_LINK;
3412 		if (flags & FIGNORECASE)
3413 			txtype |= TX_CI;
3414 		zfs_log_link(zilog, tx, txtype, dzp, szp, name);
3415 	}
3416 
3417 	dmu_tx_commit(tx);
3418 
3419 	zfs_dirent_unlock(dl);
3420 
3421 	if (error == 0) {
3422 		vnevent_link(svp, ct);
3423 	}
3424 
3425 	ZFS_EXIT(zfsvfs);
3426 	return (error);
3427 }
3428 
3429 /*
3430  * zfs_null_putapage() is used when the file system has been force
3431  * unmounted. It just drops the pages.
3432  */
3433 /* ARGSUSED */
3434 static int
3435 zfs_null_putapage(vnode_t *vp, page_t *pp, u_offset_t *offp,
3436 		size_t *lenp, int flags, cred_t *cr)
3437 {
3438 	pvn_write_done(pp, B_INVAL|B_FORCE|B_ERROR);
3439 	return (0);
3440 }
3441 
3442 /*
3443  * Push a page out to disk, klustering if possible.
3444  *
3445  *	IN:	vp	- file to push page to.
3446  *		pp	- page to push.
3447  *		flags	- additional flags.
3448  *		cr	- credentials of caller.
3449  *
3450  *	OUT:	offp	- start of range pushed.
3451  *		lenp	- len of range pushed.
3452  *
3453  *	RETURN:	0 if success
3454  *		error code if failure
3455  *
3456  * NOTE: callers must have locked the page to be pushed.  On
3457  * exit, the page (and all other pages in the kluster) must be
3458  * unlocked.
3459  */
3460 /* ARGSUSED */
3461 static int
3462 zfs_putapage(vnode_t *vp, page_t *pp, u_offset_t *offp,
3463 		size_t *lenp, int flags, cred_t *cr)
3464 {
3465 	znode_t		*zp = VTOZ(vp);
3466 	zfsvfs_t	*zfsvfs = zp->z_zfsvfs;
3467 	zilog_t		*zilog = zfsvfs->z_log;
3468 	dmu_tx_t	*tx;
3469 	rl_t		*rl;
3470 	u_offset_t	off, koff;
3471 	size_t		len, klen;
3472 	uint64_t	filesz;
3473 	int		err;
3474 
3475 	filesz = zp->z_phys->zp_size;
3476 	off = pp->p_offset;
3477 	len = PAGESIZE;
3478 	/*
3479 	 * If our blocksize is bigger than the page size, try to kluster
3480 	 * muiltiple pages so that we write a full block (thus avoiding
3481 	 * a read-modify-write).
3482 	 */
3483 	if (off < filesz && zp->z_blksz > PAGESIZE) {
3484 		if (!ISP2(zp->z_blksz)) {
3485 			/* Only one block in the file. */
3486 			klen = P2ROUNDUP((ulong_t)zp->z_blksz, PAGESIZE);
3487 			koff = 0;
3488 		} else {
3489 			klen = zp->z_blksz;
3490 			koff = P2ALIGN(off, (u_offset_t)klen);
3491 		}
3492 		ASSERT(koff <= filesz);
3493 		if (koff + klen > filesz)
3494 			klen = P2ROUNDUP(filesz - koff, (uint64_t)PAGESIZE);
3495 		pp = pvn_write_kluster(vp, pp, &off, &len, koff, klen, flags);
3496 	}
3497 	ASSERT3U(btop(len), ==, btopr(len));
3498 top:
3499 	rl = zfs_range_lock(zp, off, len, RL_WRITER);
3500 	/*
3501 	 * Can't push pages past end-of-file.
3502 	 */
3503 	filesz = zp->z_phys->zp_size;
3504 	if (off >= filesz) {
3505 		/* ignore all pages */
3506 		err = 0;
3507 		goto out;
3508 	} else if (off + len > filesz) {
3509 		int npages = btopr(filesz - off);
3510 		page_t *trunc;
3511 
3512 		page_list_break(&pp, &trunc, npages);
3513 		/* ignore pages past end of file */
3514 		if (trunc)
3515 			pvn_write_done(trunc, flags);
3516 		len = filesz - off;
3517 	}
3518 
3519 	tx = dmu_tx_create(zfsvfs->z_os);
3520 	dmu_tx_hold_write(tx, zp->z_id, off, len);
3521 	dmu_tx_hold_bonus(tx, zp->z_id);
3522 	err = dmu_tx_assign(tx, zfsvfs->z_assign);
3523 	if (err != 0) {
3524 		if (err == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) {
3525 			zfs_range_unlock(rl);
3526 			dmu_tx_wait(tx);
3527 			dmu_tx_abort(tx);
3528 			err = 0;
3529 			goto top;
3530 		}
3531 		dmu_tx_abort(tx);
3532 		goto out;
3533 	}
3534 
3535 	if (zp->z_blksz <= PAGESIZE) {
3536 		caddr_t va = ppmapin(pp, PROT_READ, (caddr_t)-1);
3537 		ASSERT3U(len, <=, PAGESIZE);
3538 		dmu_write(zfsvfs->z_os, zp->z_id, off, len, va, tx);
3539 		ppmapout(va);
3540 	} else {
3541 		err = dmu_write_pages(zfsvfs->z_os, zp->z_id, off, len, pp, tx);
3542 	}
3543 
3544 	if (err == 0) {
3545 		zfs_time_stamper(zp, CONTENT_MODIFIED, tx);
3546 		zfs_log_write(zilog, tx, TX_WRITE, zp, off, len, 0);
3547 		dmu_tx_commit(tx);
3548 	}
3549 
3550 out:
3551 	zfs_range_unlock(rl);
3552 	pvn_write_done(pp, (err ? B_ERROR : 0) | flags);
3553 	if (offp)
3554 		*offp = off;
3555 	if (lenp)
3556 		*lenp = len;
3557 
3558 	return (err);
3559 }
3560 
3561 /*
3562  * Copy the portion of the file indicated from pages into the file.
3563  * The pages are stored in a page list attached to the files vnode.
3564  *
3565  *	IN:	vp	- vnode of file to push page data to.
3566  *		off	- position in file to put data.
3567  *		len	- amount of data to write.
3568  *		flags	- flags to control the operation.
3569  *		cr	- credentials of caller.
3570  *		ct	- caller context.
3571  *
3572  *	RETURN:	0 if success
3573  *		error code if failure
3574  *
3575  * Timestamps:
3576  *	vp - ctime|mtime updated
3577  */
3578 /*ARGSUSED*/
3579 static int
3580 zfs_putpage(vnode_t *vp, offset_t off, size_t len, int flags, cred_t *cr,
3581     caller_context_t *ct)
3582 {
3583 	znode_t		*zp = VTOZ(vp);
3584 	zfsvfs_t	*zfsvfs = zp->z_zfsvfs;
3585 	page_t		*pp;
3586 	size_t		io_len;
3587 	u_offset_t	io_off;
3588 	uint64_t	filesz;
3589 	int		error = 0;
3590 
3591 	ZFS_ENTER(zfsvfs);
3592 	ZFS_VERIFY_ZP(zp);
3593 
3594 	if (len == 0) {
3595 		/*
3596 		 * Search the entire vp list for pages >= off.
3597 		 */
3598 		error = pvn_vplist_dirty(vp, (u_offset_t)off, zfs_putapage,
3599 		    flags, cr);
3600 		goto out;
3601 	}
3602 
3603 	filesz = zp->z_phys->zp_size; /* get consistent copy of zp_size */
3604 	if (off > filesz) {
3605 		/* past end of file */
3606 		ZFS_EXIT(zfsvfs);
3607 		return (0);
3608 	}
3609 
3610 	len = MIN(len, filesz - off);
3611 
3612 	for (io_off = off; io_off < off + len; io_off += io_len) {
3613 		if ((flags & B_INVAL) || ((flags & B_ASYNC) == 0)) {
3614 			pp = page_lookup(vp, io_off,
3615 			    (flags & (B_INVAL | B_FREE)) ? SE_EXCL : SE_SHARED);
3616 		} else {
3617 			pp = page_lookup_nowait(vp, io_off,
3618 			    (flags & B_FREE) ? SE_EXCL : SE_SHARED);
3619 		}
3620 
3621 		if (pp != NULL && pvn_getdirty(pp, flags)) {
3622 			int err;
3623 
3624 			/*
3625 			 * Found a dirty page to push
3626 			 */
3627 			err = zfs_putapage(vp, pp, &io_off, &io_len, flags, cr);
3628 			if (err)
3629 				error = err;
3630 		} else {
3631 			io_len = PAGESIZE;
3632 		}
3633 	}
3634 out:
3635 	if ((flags & B_ASYNC) == 0)
3636 		zil_commit(zfsvfs->z_log, UINT64_MAX, zp->z_id);
3637 	ZFS_EXIT(zfsvfs);
3638 	return (error);
3639 }
3640 
3641 /*ARGSUSED*/
3642 void
3643 zfs_inactive(vnode_t *vp, cred_t *cr, caller_context_t *ct)
3644 {
3645 	znode_t	*zp = VTOZ(vp);
3646 	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
3647 	int error;
3648 
3649 	rw_enter(&zfsvfs->z_teardown_inactive_lock, RW_READER);
3650 	if (zp->z_dbuf == NULL) {
3651 		/*
3652 		 * This fs has been unmounted, or we did
3653 		 * zfs_suspend/resume and it no longer exists.
3654 		 */
3655 		if (vn_has_cached_data(vp)) {
3656 			(void) pvn_vplist_dirty(vp, 0, zfs_null_putapage,
3657 			    B_INVAL, cr);
3658 		}
3659 
3660 		mutex_enter(&zp->z_lock);
3661 		vp->v_count = 0; /* count arrives as 1 */
3662 		mutex_exit(&zp->z_lock);
3663 		zfs_znode_free(zp);
3664 		rw_exit(&zfsvfs->z_teardown_inactive_lock);
3665 		VFS_RELE(zfsvfs->z_vfs);
3666 		return;
3667 	}
3668 
3669 	/*
3670 	 * Attempt to push any data in the page cache.  If this fails
3671 	 * we will get kicked out later in zfs_zinactive().
3672 	 */
3673 	if (vn_has_cached_data(vp)) {
3674 		(void) pvn_vplist_dirty(vp, 0, zfs_putapage, B_INVAL|B_ASYNC,
3675 		    cr);
3676 	}
3677 
3678 	if (zp->z_atime_dirty && zp->z_unlinked == 0) {
3679 		dmu_tx_t *tx = dmu_tx_create(zfsvfs->z_os);
3680 
3681 		dmu_tx_hold_bonus(tx, zp->z_id);
3682 		error = dmu_tx_assign(tx, TXG_WAIT);
3683 		if (error) {
3684 			dmu_tx_abort(tx);
3685 		} else {
3686 			dmu_buf_will_dirty(zp->z_dbuf, tx);
3687 			mutex_enter(&zp->z_lock);
3688 			zp->z_atime_dirty = 0;
3689 			mutex_exit(&zp->z_lock);
3690 			dmu_tx_commit(tx);
3691 		}
3692 	}
3693 
3694 	zfs_zinactive(zp);
3695 	rw_exit(&zfsvfs->z_teardown_inactive_lock);
3696 }
3697 
3698 /*
3699  * Bounds-check the seek operation.
3700  *
3701  *	IN:	vp	- vnode seeking within
3702  *		ooff	- old file offset
3703  *		noffp	- pointer to new file offset
3704  *		ct	- caller context
3705  *
3706  *	RETURN:	0 if success
3707  *		EINVAL if new offset invalid
3708  */
3709 /* ARGSUSED */
3710 static int
3711 zfs_seek(vnode_t *vp, offset_t ooff, offset_t *noffp,
3712     caller_context_t *ct)
3713 {
3714 	if (vp->v_type == VDIR)
3715 		return (0);
3716 	return ((*noffp < 0 || *noffp > MAXOFFSET_T) ? EINVAL : 0);
3717 }
3718 
3719 /*
3720  * Pre-filter the generic locking function to trap attempts to place
3721  * a mandatory lock on a memory mapped file.
3722  */
3723 static int
3724 zfs_frlock(vnode_t *vp, int cmd, flock64_t *bfp, int flag, offset_t offset,
3725     flk_callback_t *flk_cbp, cred_t *cr, caller_context_t *ct)
3726 {
3727 	znode_t *zp = VTOZ(vp);
3728 	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
3729 	int error;
3730 
3731 	ZFS_ENTER(zfsvfs);
3732 	ZFS_VERIFY_ZP(zp);
3733 
3734 	/*
3735 	 * We are following the UFS semantics with respect to mapcnt
3736 	 * here: If we see that the file is mapped already, then we will
3737 	 * return an error, but we don't worry about races between this
3738 	 * function and zfs_map().
3739 	 */
3740 	if (zp->z_mapcnt > 0 && MANDMODE((mode_t)zp->z_phys->zp_mode)) {
3741 		ZFS_EXIT(zfsvfs);
3742 		return (EAGAIN);
3743 	}
3744 	error = fs_frlock(vp, cmd, bfp, flag, offset, flk_cbp, cr, ct);
3745 	ZFS_EXIT(zfsvfs);
3746 	return (error);
3747 }
3748 
3749 /*
3750  * If we can't find a page in the cache, we will create a new page
3751  * and fill it with file data.  For efficiency, we may try to fill
3752  * multiple pages at once (klustering).
3753  */
3754 static int
3755 zfs_fillpage(vnode_t *vp, u_offset_t off, struct seg *seg,
3756     caddr_t addr, page_t *pl[], size_t plsz, enum seg_rw rw)
3757 {
3758 	znode_t *zp = VTOZ(vp);
3759 	page_t *pp, *cur_pp;
3760 	objset_t *os = zp->z_zfsvfs->z_os;
3761 	caddr_t va;
3762 	u_offset_t io_off, total;
3763 	uint64_t oid = zp->z_id;
3764 	size_t io_len;
3765 	uint64_t filesz;
3766 	int err;
3767 
3768 	/*
3769 	 * If we are only asking for a single page don't bother klustering.
3770 	 */
3771 	filesz = zp->z_phys->zp_size; /* get consistent copy of zp_size */
3772 	if (off >= filesz)
3773 		return (EFAULT);
3774 	if (plsz == PAGESIZE || zp->z_blksz <= PAGESIZE) {
3775 		io_off = off;
3776 		io_len = PAGESIZE;
3777 		pp = page_create_va(vp, io_off, io_len, PG_WAIT, seg, addr);
3778 	} else {
3779 		/*
3780 		 * Try to fill a kluster of pages (a blocks worth).
3781 		 */
3782 		size_t klen;
3783 		u_offset_t koff;
3784 
3785 		if (!ISP2(zp->z_blksz)) {
3786 			/* Only one block in the file. */
3787 			klen = P2ROUNDUP((ulong_t)zp->z_blksz, PAGESIZE);
3788 			koff = 0;
3789 		} else {
3790 			/*
3791 			 * It would be ideal to align our offset to the
3792 			 * blocksize but doing so has resulted in some
3793 			 * strange application crashes. For now, we
3794 			 * leave the offset as is and only adjust the
3795 			 * length if we are off the end of the file.
3796 			 */
3797 			koff = off;
3798 			klen = plsz;
3799 		}
3800 		ASSERT(koff <= filesz);
3801 		if (koff + klen > filesz)
3802 			klen = P2ROUNDUP(filesz, (uint64_t)PAGESIZE) - koff;
3803 		ASSERT3U(off, >=, koff);
3804 		ASSERT3U(off, <, koff + klen);
3805 		pp = pvn_read_kluster(vp, off, seg, addr, &io_off,
3806 		    &io_len, koff, klen, 0);
3807 	}
3808 	if (pp == NULL) {
3809 		/*
3810 		 * Some other thread entered the page before us.
3811 		 * Return to zfs_getpage to retry the lookup.
3812 		 */
3813 		*pl = NULL;
3814 		return (0);
3815 	}
3816 
3817 	/*
3818 	 * Fill the pages in the kluster.
3819 	 */
3820 	cur_pp = pp;
3821 	for (total = io_off + io_len; io_off < total; io_off += PAGESIZE) {
3822 		ASSERT3U(io_off, ==, cur_pp->p_offset);
3823 		va = ppmapin(cur_pp, PROT_READ | PROT_WRITE, (caddr_t)-1);
3824 		err = dmu_read(os, oid, io_off, PAGESIZE, va);
3825 		ppmapout(va);
3826 		if (err) {
3827 			/* On error, toss the entire kluster */
3828 			pvn_read_done(pp, B_ERROR);
3829 			return (err);
3830 		}
3831 		cur_pp = cur_pp->p_next;
3832 	}
3833 out:
3834 	/*
3835 	 * Fill in the page list array from the kluster.  If
3836 	 * there are too many pages in the kluster, return
3837 	 * as many pages as possible starting from the desired
3838 	 * offset `off'.
3839 	 * NOTE: the page list will always be null terminated.
3840 	 */
3841 	pvn_plist_init(pp, pl, plsz, off, io_len, rw);
3842 
3843 	return (0);
3844 }
3845 
3846 /*
3847  * Return pointers to the pages for the file region [off, off + len]
3848  * in the pl array.  If plsz is greater than len, this function may
3849  * also return page pointers from before or after the specified
3850  * region (i.e. some region [off', off' + plsz]).  These additional
3851  * pages are only returned if they are already in the cache, or were
3852  * created as part of a klustered read.
3853  *
3854  *	IN:	vp	- vnode of file to get data from.
3855  *		off	- position in file to get data from.
3856  *		len	- amount of data to retrieve.
3857  *		plsz	- length of provided page list.
3858  *		seg	- segment to obtain pages for.
3859  *		addr	- virtual address of fault.
3860  *		rw	- mode of created pages.
3861  *		cr	- credentials of caller.
3862  *		ct	- caller context.
3863  *
3864  *	OUT:	protp	- protection mode of created pages.
3865  *		pl	- list of pages created.
3866  *
3867  *	RETURN:	0 if success
3868  *		error code if failure
3869  *
3870  * Timestamps:
3871  *	vp - atime updated
3872  */
3873 /* ARGSUSED */
3874 static int
3875 zfs_getpage(vnode_t *vp, offset_t off, size_t len, uint_t *protp,
3876 	page_t *pl[], size_t plsz, struct seg *seg, caddr_t addr,
3877 	enum seg_rw rw, cred_t *cr, caller_context_t *ct)
3878 {
3879 	znode_t		*zp = VTOZ(vp);
3880 	zfsvfs_t	*zfsvfs = zp->z_zfsvfs;
3881 	page_t		*pp, **pl0 = pl;
3882 	int		need_unlock = 0, err = 0;
3883 	offset_t	orig_off;
3884 
3885 	ZFS_ENTER(zfsvfs);
3886 	ZFS_VERIFY_ZP(zp);
3887 
3888 	if (protp)
3889 		*protp = PROT_ALL;
3890 
3891 	/* no faultahead (for now) */
3892 	if (pl == NULL) {
3893 		ZFS_EXIT(zfsvfs);
3894 		return (0);
3895 	}
3896 
3897 	/* can't fault past EOF */
3898 	if (off >= zp->z_phys->zp_size) {
3899 		ZFS_EXIT(zfsvfs);
3900 		return (EFAULT);
3901 	}
3902 	orig_off = off;
3903 
3904 	/*
3905 	 * If we already own the lock, then we must be page faulting
3906 	 * in the middle of a write to this file (i.e., we are writing
3907 	 * to this file using data from a mapped region of the file).
3908 	 */
3909 	if (rw_owner(&zp->z_map_lock) != curthread) {
3910 		rw_enter(&zp->z_map_lock, RW_WRITER);
3911 		need_unlock = TRUE;
3912 	}
3913 
3914 	/*
3915 	 * Loop through the requested range [off, off + len] looking
3916 	 * for pages.  If we don't find a page, we will need to create
3917 	 * a new page and fill it with data from the file.
3918 	 */
3919 	while (len > 0) {
3920 		if (plsz < PAGESIZE)
3921 			break;
3922 		if (pp = page_lookup(vp, off, SE_SHARED)) {
3923 			*pl++ = pp;
3924 			off += PAGESIZE;
3925 			addr += PAGESIZE;
3926 			len -= PAGESIZE;
3927 			plsz -= PAGESIZE;
3928 		} else {
3929 			err = zfs_fillpage(vp, off, seg, addr, pl, plsz, rw);
3930 			if (err)
3931 				goto out;
3932 			/*
3933 			 * klustering may have changed our region
3934 			 * to be block aligned.
3935 			 */
3936 			if (((pp = *pl) != 0) && (off != pp->p_offset)) {
3937 				int delta = off - pp->p_offset;
3938 				len += delta;
3939 				off -= delta;
3940 				addr -= delta;
3941 			}
3942 			while (*pl) {
3943 				pl++;
3944 				off += PAGESIZE;
3945 				addr += PAGESIZE;
3946 				plsz -= PAGESIZE;
3947 				if (len > PAGESIZE)
3948 					len -= PAGESIZE;
3949 				else
3950 					len = 0;
3951 			}
3952 		}
3953 	}
3954 
3955 	/*
3956 	 * Fill out the page array with any pages already in the cache.
3957 	 */
3958 	while (plsz > 0) {
3959 		pp = page_lookup_nowait(vp, off, SE_SHARED);
3960 		if (pp == NULL)
3961 			break;
3962 		*pl++ = pp;
3963 		off += PAGESIZE;
3964 		plsz -= PAGESIZE;
3965 	}
3966 
3967 	ZFS_ACCESSTIME_STAMP(zfsvfs, zp);
3968 out:
3969 	/*
3970 	 * We can't grab the range lock for the page as reader which would
3971 	 * stop truncation as this leads to deadlock. So we need to recheck
3972 	 * the file size.
3973 	 */
3974 	if (orig_off >= zp->z_phys->zp_size)
3975 		err = EFAULT;
3976 	if (err) {
3977 		/*
3978 		 * Release any pages we have previously locked.
3979 		 */
3980 		while (pl > pl0)
3981 			page_unlock(*--pl);
3982 	}
3983 
3984 	*pl = NULL;
3985 
3986 	if (need_unlock)
3987 		rw_exit(&zp->z_map_lock);
3988 
3989 	ZFS_EXIT(zfsvfs);
3990 	return (err);
3991 }
3992 
3993 /*
3994  * Request a memory map for a section of a file.  This code interacts
3995  * with common code and the VM system as follows:
3996  *
3997  *	common code calls mmap(), which ends up in smmap_common()
3998  *
3999  *	this calls VOP_MAP(), which takes you into (say) zfs
4000  *
4001  *	zfs_map() calls as_map(), passing segvn_create() as the callback
4002  *
4003  *	segvn_create() creates the new segment and calls VOP_ADDMAP()
4004  *
4005  *	zfs_addmap() updates z_mapcnt
4006  */
4007 /*ARGSUSED*/
4008 static int
4009 zfs_map(vnode_t *vp, offset_t off, struct as *as, caddr_t *addrp,
4010     size_t len, uchar_t prot, uchar_t maxprot, uint_t flags, cred_t *cr,
4011     caller_context_t *ct)
4012 {
4013 	znode_t *zp = VTOZ(vp);
4014 	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
4015 	segvn_crargs_t	vn_a;
4016 	int		error;
4017 
4018 	if ((prot & PROT_WRITE) &&
4019 	    (zp->z_phys->zp_flags & (ZFS_IMMUTABLE | ZFS_READONLY |
4020 	    ZFS_APPENDONLY)))
4021 		return (EPERM);
4022 
4023 	ZFS_ENTER(zfsvfs);
4024 	ZFS_VERIFY_ZP(zp);
4025 
4026 	if (vp->v_flag & VNOMAP) {
4027 		ZFS_EXIT(zfsvfs);
4028 		return (ENOSYS);
4029 	}
4030 
4031 	if (off < 0 || len > MAXOFFSET_T - off) {
4032 		ZFS_EXIT(zfsvfs);
4033 		return (ENXIO);
4034 	}
4035 
4036 	if (vp->v_type != VREG) {
4037 		ZFS_EXIT(zfsvfs);
4038 		return (ENODEV);
4039 	}
4040 
4041 	/*
4042 	 * If file is locked, disallow mapping.
4043 	 */
4044 	if (MANDMODE((mode_t)zp->z_phys->zp_mode) && vn_has_flocks(vp)) {
4045 		ZFS_EXIT(zfsvfs);
4046 		return (EAGAIN);
4047 	}
4048 
4049 	as_rangelock(as);
4050 	if ((flags & MAP_FIXED) == 0) {
4051 		map_addr(addrp, len, off, 1, flags);
4052 		if (*addrp == NULL) {
4053 			as_rangeunlock(as);
4054 			ZFS_EXIT(zfsvfs);
4055 			return (ENOMEM);
4056 		}
4057 	} else {
4058 		/*
4059 		 * User specified address - blow away any previous mappings
4060 		 */
4061 		(void) as_unmap(as, *addrp, len);
4062 	}
4063 
4064 	vn_a.vp = vp;
4065 	vn_a.offset = (u_offset_t)off;
4066 	vn_a.type = flags & MAP_TYPE;
4067 	vn_a.prot = prot;
4068 	vn_a.maxprot = maxprot;
4069 	vn_a.cred = cr;
4070 	vn_a.amp = NULL;
4071 	vn_a.flags = flags & ~MAP_TYPE;
4072 	vn_a.szc = 0;
4073 	vn_a.lgrp_mem_policy_flags = 0;
4074 
4075 	error = as_map(as, *addrp, len, segvn_create, &vn_a);
4076 
4077 	as_rangeunlock(as);
4078 	ZFS_EXIT(zfsvfs);
4079 	return (error);
4080 }
4081 
4082 /* ARGSUSED */
4083 static int
4084 zfs_addmap(vnode_t *vp, offset_t off, struct as *as, caddr_t addr,
4085     size_t len, uchar_t prot, uchar_t maxprot, uint_t flags, cred_t *cr,
4086     caller_context_t *ct)
4087 {
4088 	uint64_t pages = btopr(len);
4089 
4090 	atomic_add_64(&VTOZ(vp)->z_mapcnt, pages);
4091 	return (0);
4092 }
4093 
4094 /*
4095  * The reason we push dirty pages as part of zfs_delmap() is so that we get a
4096  * more accurate mtime for the associated file.  Since we don't have a way of
4097  * detecting when the data was actually modified, we have to resort to
4098  * heuristics.  If an explicit msync() is done, then we mark the mtime when the
4099  * last page is pushed.  The problem occurs when the msync() call is omitted,
4100  * which by far the most common case:
4101  *
4102  * 	open()
4103  * 	mmap()
4104  * 	<modify memory>
4105  * 	munmap()
4106  * 	close()
4107  * 	<time lapse>
4108  * 	putpage() via fsflush
4109  *
4110  * If we wait until fsflush to come along, we can have a modification time that
4111  * is some arbitrary point in the future.  In order to prevent this in the
4112  * common case, we flush pages whenever a (MAP_SHARED, PROT_WRITE) mapping is
4113  * torn down.
4114  */
4115 /* ARGSUSED */
4116 static int
4117 zfs_delmap(vnode_t *vp, offset_t off, struct as *as, caddr_t addr,
4118     size_t len, uint_t prot, uint_t maxprot, uint_t flags, cred_t *cr,
4119     caller_context_t *ct)
4120 {
4121 	uint64_t pages = btopr(len);
4122 
4123 	ASSERT3U(VTOZ(vp)->z_mapcnt, >=, pages);
4124 	atomic_add_64(&VTOZ(vp)->z_mapcnt, -pages);
4125 
4126 	if ((flags & MAP_SHARED) && (prot & PROT_WRITE) &&
4127 	    vn_has_cached_data(vp))
4128 		(void) VOP_PUTPAGE(vp, off, len, B_ASYNC, cr, ct);
4129 
4130 	return (0);
4131 }
4132 
4133 /*
4134  * Free or allocate space in a file.  Currently, this function only
4135  * supports the `F_FREESP' command.  However, this command is somewhat
4136  * misnamed, as its functionality includes the ability to allocate as
4137  * well as free space.
4138  *
4139  *	IN:	vp	- vnode of file to free data in.
4140  *		cmd	- action to take (only F_FREESP supported).
4141  *		bfp	- section of file to free/alloc.
4142  *		flag	- current file open mode flags.
4143  *		offset	- current file offset.
4144  *		cr	- credentials of caller [UNUSED].
4145  *		ct	- caller context.
4146  *
4147  *	RETURN:	0 if success
4148  *		error code if failure
4149  *
4150  * Timestamps:
4151  *	vp - ctime|mtime updated
4152  */
4153 /* ARGSUSED */
4154 static int
4155 zfs_space(vnode_t *vp, int cmd, flock64_t *bfp, int flag,
4156     offset_t offset, cred_t *cr, caller_context_t *ct)
4157 {
4158 	znode_t		*zp = VTOZ(vp);
4159 	zfsvfs_t	*zfsvfs = zp->z_zfsvfs;
4160 	uint64_t	off, len;
4161 	int		error;
4162 
4163 	ZFS_ENTER(zfsvfs);
4164 	ZFS_VERIFY_ZP(zp);
4165 
4166 top:
4167 	if (cmd != F_FREESP) {
4168 		ZFS_EXIT(zfsvfs);
4169 		return (EINVAL);
4170 	}
4171 
4172 	if (error = convoff(vp, bfp, 0, offset)) {
4173 		ZFS_EXIT(zfsvfs);
4174 		return (error);
4175 	}
4176 
4177 	if (bfp->l_len < 0) {
4178 		ZFS_EXIT(zfsvfs);
4179 		return (EINVAL);
4180 	}
4181 
4182 	off = bfp->l_start;
4183 	len = bfp->l_len; /* 0 means from off to end of file */
4184 
4185 	do {
4186 		error = zfs_freesp(zp, off, len, flag, TRUE);
4187 		/* NB: we already did dmu_tx_wait() if necessary */
4188 	} while (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT);
4189 
4190 	ZFS_EXIT(zfsvfs);
4191 	return (error);
4192 }
4193 
4194 /*ARGSUSED*/
4195 static int
4196 zfs_fid(vnode_t *vp, fid_t *fidp, caller_context_t *ct)
4197 {
4198 	znode_t		*zp = VTOZ(vp);
4199 	zfsvfs_t	*zfsvfs = zp->z_zfsvfs;
4200 	uint32_t	gen;
4201 	uint64_t	object = zp->z_id;
4202 	zfid_short_t	*zfid;
4203 	int		size, i;
4204 
4205 	ZFS_ENTER(zfsvfs);
4206 	ZFS_VERIFY_ZP(zp);
4207 	gen = (uint32_t)zp->z_gen;
4208 
4209 	size = (zfsvfs->z_parent != zfsvfs) ? LONG_FID_LEN : SHORT_FID_LEN;
4210 	if (fidp->fid_len < size) {
4211 		fidp->fid_len = size;
4212 		ZFS_EXIT(zfsvfs);
4213 		return (ENOSPC);
4214 	}
4215 
4216 	zfid = (zfid_short_t *)fidp;
4217 
4218 	zfid->zf_len = size;
4219 
4220 	for (i = 0; i < sizeof (zfid->zf_object); i++)
4221 		zfid->zf_object[i] = (uint8_t)(object >> (8 * i));
4222 
4223 	/* Must have a non-zero generation number to distinguish from .zfs */
4224 	if (gen == 0)
4225 		gen = 1;
4226 	for (i = 0; i < sizeof (zfid->zf_gen); i++)
4227 		zfid->zf_gen[i] = (uint8_t)(gen >> (8 * i));
4228 
4229 	if (size == LONG_FID_LEN) {
4230 		uint64_t	objsetid = dmu_objset_id(zfsvfs->z_os);
4231 		zfid_long_t	*zlfid;
4232 
4233 		zlfid = (zfid_long_t *)fidp;
4234 
4235 		for (i = 0; i < sizeof (zlfid->zf_setid); i++)
4236 			zlfid->zf_setid[i] = (uint8_t)(objsetid >> (8 * i));
4237 
4238 		/* XXX - this should be the generation number for the objset */
4239 		for (i = 0; i < sizeof (zlfid->zf_setgen); i++)
4240 			zlfid->zf_setgen[i] = 0;
4241 	}
4242 
4243 	ZFS_EXIT(zfsvfs);
4244 	return (0);
4245 }
4246 
4247 static int
4248 zfs_pathconf(vnode_t *vp, int cmd, ulong_t *valp, cred_t *cr,
4249     caller_context_t *ct)
4250 {
4251 	znode_t		*zp, *xzp;
4252 	zfsvfs_t	*zfsvfs;
4253 	zfs_dirlock_t	*dl;
4254 	int		error;
4255 
4256 	switch (cmd) {
4257 	case _PC_LINK_MAX:
4258 		*valp = ULONG_MAX;
4259 		return (0);
4260 
4261 	case _PC_FILESIZEBITS:
4262 		*valp = 64;
4263 		return (0);
4264 
4265 	case _PC_XATTR_EXISTS:
4266 		zp = VTOZ(vp);
4267 		zfsvfs = zp->z_zfsvfs;
4268 		ZFS_ENTER(zfsvfs);
4269 		ZFS_VERIFY_ZP(zp);
4270 		*valp = 0;
4271 		error = zfs_dirent_lock(&dl, zp, "", &xzp,
4272 		    ZXATTR | ZEXISTS | ZSHARED, NULL, NULL);
4273 		if (error == 0) {
4274 			zfs_dirent_unlock(dl);
4275 			if (!zfs_dirempty(xzp))
4276 				*valp = 1;
4277 			VN_RELE(ZTOV(xzp));
4278 		} else if (error == ENOENT) {
4279 			/*
4280 			 * If there aren't extended attributes, it's the
4281 			 * same as having zero of them.
4282 			 */
4283 			error = 0;
4284 		}
4285 		ZFS_EXIT(zfsvfs);
4286 		return (error);
4287 
4288 	case _PC_SATTR_ENABLED:
4289 	case _PC_SATTR_EXISTS:
4290 		*valp = vfs_has_feature(vp->v_vfsp, VFSFT_XVATTR) &&
4291 		    (vp->v_type == VREG || vp->v_type == VDIR);
4292 		return (0);
4293 
4294 	case _PC_ACL_ENABLED:
4295 		*valp = _ACL_ACE_ENABLED;
4296 		return (0);
4297 
4298 	case _PC_MIN_HOLE_SIZE:
4299 		*valp = (ulong_t)SPA_MINBLOCKSIZE;
4300 		return (0);
4301 
4302 	default:
4303 		return (fs_pathconf(vp, cmd, valp, cr, ct));
4304 	}
4305 }
4306 
4307 /*ARGSUSED*/
4308 static int
4309 zfs_getsecattr(vnode_t *vp, vsecattr_t *vsecp, int flag, cred_t *cr,
4310     caller_context_t *ct)
4311 {
4312 	znode_t *zp = VTOZ(vp);
4313 	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
4314 	int error;
4315 	boolean_t skipaclchk = (flag & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE;
4316 
4317 	ZFS_ENTER(zfsvfs);
4318 	ZFS_VERIFY_ZP(zp);
4319 	error = zfs_getacl(zp, vsecp, skipaclchk, cr);
4320 	ZFS_EXIT(zfsvfs);
4321 
4322 	return (error);
4323 }
4324 
4325 /*ARGSUSED*/
4326 static int
4327 zfs_setsecattr(vnode_t *vp, vsecattr_t *vsecp, int flag, cred_t *cr,
4328     caller_context_t *ct)
4329 {
4330 	znode_t *zp = VTOZ(vp);
4331 	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
4332 	int error;
4333 	boolean_t skipaclchk = (flag & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE;
4334 
4335 	ZFS_ENTER(zfsvfs);
4336 	ZFS_VERIFY_ZP(zp);
4337 	error = zfs_setacl(zp, vsecp, skipaclchk, cr);
4338 	ZFS_EXIT(zfsvfs);
4339 	return (error);
4340 }
4341 
4342 /*
4343  * Predeclare these here so that the compiler assumes that
4344  * this is an "old style" function declaration that does
4345  * not include arguments => we won't get type mismatch errors
4346  * in the initializations that follow.
4347  */
4348 static int zfs_inval();
4349 static int zfs_isdir();
4350 
4351 static int
4352 zfs_inval()
4353 {
4354 	return (EINVAL);
4355 }
4356 
4357 static int
4358 zfs_isdir()
4359 {
4360 	return (EISDIR);
4361 }
4362 /*
4363  * Directory vnode operations template
4364  */
4365 vnodeops_t *zfs_dvnodeops;
4366 const fs_operation_def_t zfs_dvnodeops_template[] = {
4367 	VOPNAME_OPEN,		{ .vop_open = zfs_open },
4368 	VOPNAME_CLOSE,		{ .vop_close = zfs_close },
4369 	VOPNAME_READ,		{ .error = zfs_isdir },
4370 	VOPNAME_WRITE,		{ .error = zfs_isdir },
4371 	VOPNAME_IOCTL,		{ .vop_ioctl = zfs_ioctl },
4372 	VOPNAME_GETATTR,	{ .vop_getattr = zfs_getattr },
4373 	VOPNAME_SETATTR,	{ .vop_setattr = zfs_setattr },
4374 	VOPNAME_ACCESS,		{ .vop_access = zfs_access },
4375 	VOPNAME_LOOKUP,		{ .vop_lookup = zfs_lookup },
4376 	VOPNAME_CREATE,		{ .vop_create = zfs_create },
4377 	VOPNAME_REMOVE,		{ .vop_remove = zfs_remove },
4378 	VOPNAME_LINK,		{ .vop_link = zfs_link },
4379 	VOPNAME_RENAME,		{ .vop_rename = zfs_rename },
4380 	VOPNAME_MKDIR,		{ .vop_mkdir = zfs_mkdir },
4381 	VOPNAME_RMDIR,		{ .vop_rmdir = zfs_rmdir },
4382 	VOPNAME_READDIR,	{ .vop_readdir = zfs_readdir },
4383 	VOPNAME_SYMLINK,	{ .vop_symlink = zfs_symlink },
4384 	VOPNAME_FSYNC,		{ .vop_fsync = zfs_fsync },
4385 	VOPNAME_INACTIVE,	{ .vop_inactive = zfs_inactive },
4386 	VOPNAME_FID,		{ .vop_fid = zfs_fid },
4387 	VOPNAME_SEEK,		{ .vop_seek = zfs_seek },
4388 	VOPNAME_PATHCONF,	{ .vop_pathconf = zfs_pathconf },
4389 	VOPNAME_GETSECATTR,	{ .vop_getsecattr = zfs_getsecattr },
4390 	VOPNAME_SETSECATTR,	{ .vop_setsecattr = zfs_setsecattr },
4391 	VOPNAME_VNEVENT, 	{ .vop_vnevent = fs_vnevent_support },
4392 	NULL,			NULL
4393 };
4394 
4395 /*
4396  * Regular file vnode operations template
4397  */
4398 vnodeops_t *zfs_fvnodeops;
4399 const fs_operation_def_t zfs_fvnodeops_template[] = {
4400 	VOPNAME_OPEN,		{ .vop_open = zfs_open },
4401 	VOPNAME_CLOSE,		{ .vop_close = zfs_close },
4402 	VOPNAME_READ,		{ .vop_read = zfs_read },
4403 	VOPNAME_WRITE,		{ .vop_write = zfs_write },
4404 	VOPNAME_IOCTL,		{ .vop_ioctl = zfs_ioctl },
4405 	VOPNAME_GETATTR,	{ .vop_getattr = zfs_getattr },
4406 	VOPNAME_SETATTR,	{ .vop_setattr = zfs_setattr },
4407 	VOPNAME_ACCESS,		{ .vop_access = zfs_access },
4408 	VOPNAME_LOOKUP,		{ .vop_lookup = zfs_lookup },
4409 	VOPNAME_RENAME,		{ .vop_rename = zfs_rename },
4410 	VOPNAME_FSYNC,		{ .vop_fsync = zfs_fsync },
4411 	VOPNAME_INACTIVE,	{ .vop_inactive = zfs_inactive },
4412 	VOPNAME_FID,		{ .vop_fid = zfs_fid },
4413 	VOPNAME_SEEK,		{ .vop_seek = zfs_seek },
4414 	VOPNAME_FRLOCK,		{ .vop_frlock = zfs_frlock },
4415 	VOPNAME_SPACE,		{ .vop_space = zfs_space },
4416 	VOPNAME_GETPAGE,	{ .vop_getpage = zfs_getpage },
4417 	VOPNAME_PUTPAGE,	{ .vop_putpage = zfs_putpage },
4418 	VOPNAME_MAP,		{ .vop_map = zfs_map },
4419 	VOPNAME_ADDMAP,		{ .vop_addmap = zfs_addmap },
4420 	VOPNAME_DELMAP,		{ .vop_delmap = zfs_delmap },
4421 	VOPNAME_PATHCONF,	{ .vop_pathconf = zfs_pathconf },
4422 	VOPNAME_GETSECATTR,	{ .vop_getsecattr = zfs_getsecattr },
4423 	VOPNAME_SETSECATTR,	{ .vop_setsecattr = zfs_setsecattr },
4424 	VOPNAME_VNEVENT,	{ .vop_vnevent = fs_vnevent_support },
4425 	NULL,			NULL
4426 };
4427 
4428 /*
4429  * Symbolic link vnode operations template
4430  */
4431 vnodeops_t *zfs_symvnodeops;
4432 const fs_operation_def_t zfs_symvnodeops_template[] = {
4433 	VOPNAME_GETATTR,	{ .vop_getattr = zfs_getattr },
4434 	VOPNAME_SETATTR,	{ .vop_setattr = zfs_setattr },
4435 	VOPNAME_ACCESS,		{ .vop_access = zfs_access },
4436 	VOPNAME_RENAME,		{ .vop_rename = zfs_rename },
4437 	VOPNAME_READLINK,	{ .vop_readlink = zfs_readlink },
4438 	VOPNAME_INACTIVE,	{ .vop_inactive = zfs_inactive },
4439 	VOPNAME_FID,		{ .vop_fid = zfs_fid },
4440 	VOPNAME_PATHCONF,	{ .vop_pathconf = zfs_pathconf },
4441 	VOPNAME_VNEVENT,	{ .vop_vnevent = fs_vnevent_support },
4442 	NULL,			NULL
4443 };
4444 
4445 /*
4446  * Extended attribute directory vnode operations template
4447  *	This template is identical to the directory vnodes
4448  *	operation template except for restricted operations:
4449  *		VOP_MKDIR()
4450  *		VOP_SYMLINK()
4451  * Note that there are other restrictions embedded in:
4452  *	zfs_create()	- restrict type to VREG
4453  *	zfs_link()	- no links into/out of attribute space
4454  *	zfs_rename()	- no moves into/out of attribute space
4455  */
4456 vnodeops_t *zfs_xdvnodeops;
4457 const fs_operation_def_t zfs_xdvnodeops_template[] = {
4458 	VOPNAME_OPEN,		{ .vop_open = zfs_open },
4459 	VOPNAME_CLOSE,		{ .vop_close = zfs_close },
4460 	VOPNAME_IOCTL,		{ .vop_ioctl = zfs_ioctl },
4461 	VOPNAME_GETATTR,	{ .vop_getattr = zfs_getattr },
4462 	VOPNAME_SETATTR,	{ .vop_setattr = zfs_setattr },
4463 	VOPNAME_ACCESS,		{ .vop_access = zfs_access },
4464 	VOPNAME_LOOKUP,		{ .vop_lookup = zfs_lookup },
4465 	VOPNAME_CREATE,		{ .vop_create = zfs_create },
4466 	VOPNAME_REMOVE,		{ .vop_remove = zfs_remove },
4467 	VOPNAME_LINK,		{ .vop_link = zfs_link },
4468 	VOPNAME_RENAME,		{ .vop_rename = zfs_rename },
4469 	VOPNAME_MKDIR,		{ .error = zfs_inval },
4470 	VOPNAME_RMDIR,		{ .vop_rmdir = zfs_rmdir },
4471 	VOPNAME_READDIR,	{ .vop_readdir = zfs_readdir },
4472 	VOPNAME_SYMLINK,	{ .error = zfs_inval },
4473 	VOPNAME_FSYNC,		{ .vop_fsync = zfs_fsync },
4474 	VOPNAME_INACTIVE,	{ .vop_inactive = zfs_inactive },
4475 	VOPNAME_FID,		{ .vop_fid = zfs_fid },
4476 	VOPNAME_SEEK,		{ .vop_seek = zfs_seek },
4477 	VOPNAME_PATHCONF,	{ .vop_pathconf = zfs_pathconf },
4478 	VOPNAME_GETSECATTR,	{ .vop_getsecattr = zfs_getsecattr },
4479 	VOPNAME_SETSECATTR,	{ .vop_setsecattr = zfs_setsecattr },
4480 	VOPNAME_VNEVENT,	{ .vop_vnevent = fs_vnevent_support },
4481 	NULL,			NULL
4482 };
4483 
4484 /*
4485  * Error vnode operations template
4486  */
4487 vnodeops_t *zfs_evnodeops;
4488 const fs_operation_def_t zfs_evnodeops_template[] = {
4489 	VOPNAME_INACTIVE,	{ .vop_inactive = zfs_inactive },
4490 	VOPNAME_PATHCONF,	{ .vop_pathconf = zfs_pathconf },
4491 	NULL,			NULL
4492 };
4493