xref: /illumos-gate/usr/src/uts/common/fs/vnode.c (revision 22028508fd28d36ff74dc02c5774a8ba1f0db045)
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 /*
23  * Copyright (c) 1988, 2010, Oracle and/or its affiliates. All rights reserved.
24  * Copyright 2020 Joyent, Inc.
25  * Copyright 2016 Nexenta Systems, Inc.  All rights reserved.
26  * Copyright (c) 2011, 2017 by Delphix. All rights reserved.
27  */
28 
29 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
30 /*	  All Rights Reserved	*/
31 
32 /*
33  * University Copyright- Copyright (c) 1982, 1986, 1988
34  * The Regents of the University of California
35  * All Rights Reserved
36  *
37  * University Acknowledgment- Portions of this document are derived from
38  * software developed by the University of California, Berkeley, and its
39  * contributors.
40  */
41 
42 #include <sys/types.h>
43 #include <sys/param.h>
44 #include <sys/t_lock.h>
45 #include <sys/errno.h>
46 #include <sys/cred.h>
47 #include <sys/user.h>
48 #include <sys/uio.h>
49 #include <sys/file.h>
50 #include <sys/pathname.h>
51 #include <sys/vfs.h>
52 #include <sys/vfs_opreg.h>
53 #include <sys/vnode.h>
54 #include <sys/filio.h>
55 #include <sys/rwstlock.h>
56 #include <sys/fem.h>
57 #include <sys/stat.h>
58 #include <sys/mode.h>
59 #include <sys/conf.h>
60 #include <sys/sysmacros.h>
61 #include <sys/cmn_err.h>
62 #include <sys/systm.h>
63 #include <sys/kmem.h>
64 #include <sys/debug.h>
65 #include <c2/audit.h>
66 #include <sys/acl.h>
67 #include <sys/nbmlock.h>
68 #include <sys/fcntl.h>
69 #include <fs/fs_subr.h>
70 #include <sys/taskq.h>
71 #include <fs/fs_reparse.h>
72 #include <sys/time.h>
73 #include <sys/sdt.h>
74 
75 /* Determine if this vnode is a file that is read-only */
76 #define	ISROFILE(vp)	\
77 	((vp)->v_type != VCHR && (vp)->v_type != VBLK && \
78 	    (vp)->v_type != VFIFO && vn_is_readonly(vp))
79 
80 /* Tunable via /etc/system; used only by admin/install */
81 int nfs_global_client_only;
82 
83 /*
84  * Array of vopstats_t for per-FS-type vopstats.  This array has the same
85  * number of entries as and parallel to the vfssw table.  (Arguably, it could
86  * be part of the vfssw table.)  Once it's initialized, it's accessed using
87  * the same fstype index that is used to index into the vfssw table.
88  */
89 vopstats_t **vopstats_fstype;
90 
91 /* vopstats initialization template used for fast initialization via bcopy() */
92 static vopstats_t *vs_templatep;
93 
94 /* Kmem cache handle for vsk_anchor_t allocations */
95 kmem_cache_t *vsk_anchor_cache;
96 
97 /* file events cleanup routine */
98 extern void free_fopdata(vnode_t *);
99 
100 /*
101  * Root of AVL tree for the kstats associated with vopstats.  Lock protects
102  * updates to vsktat_tree.
103  */
104 avl_tree_t	vskstat_tree;
105 kmutex_t	vskstat_tree_lock;
106 
107 /* Global variable which enables/disables the vopstats collection */
108 int vopstats_enabled = 1;
109 
110 /* Global used for empty/invalid v_path */
111 char *vn_vpath_empty = "";
112 
113 /*
114  * forward declarations for internal vnode specific data (vsd)
115  */
116 static void *vsd_realloc(void *, size_t, size_t);
117 
118 /*
119  * forward declarations for reparse point functions
120  */
121 static int fs_reparse_mark(char *target, vattr_t *vap, xvattr_t *xvattr);
122 
123 /*
124  * VSD -- VNODE SPECIFIC DATA
125  * The v_data pointer is typically used by a file system to store a
126  * pointer to the file system's private node (e.g. ufs inode, nfs rnode).
127  * However, there are times when additional project private data needs
128  * to be stored separately from the data (node) pointed to by v_data.
129  * This additional data could be stored by the file system itself or
130  * by a completely different kernel entity.  VSD provides a way for
131  * callers to obtain a key and store a pointer to private data associated
132  * with a vnode.
133  *
134  * Callers are responsible for protecting the vsd by holding v_vsd_lock
135  * for calls to vsd_set() and vsd_get().
136  */
137 
138 /*
139  * vsd_lock protects:
140  *   vsd_nkeys - creation and deletion of vsd keys
141  *   vsd_list - insertion and deletion of vsd_node in the vsd_list
142  *   vsd_destructor - adding and removing destructors to the list
143  */
144 static kmutex_t		vsd_lock;
145 static uint_t		vsd_nkeys;	 /* size of destructor array */
146 /* list of vsd_node's */
147 static list_t *vsd_list = NULL;
148 /* per-key destructor funcs */
149 static void		(**vsd_destructor)(void *);
150 
151 /*
152  * The following is the common set of actions needed to update the
153  * vopstats structure from a vnode op.  Both VOPSTATS_UPDATE() and
154  * VOPSTATS_UPDATE_IO() do almost the same thing, except for the
155  * recording of the bytes transferred.  Since the code is similar
156  * but small, it is nearly a duplicate.  Consequently any changes
157  * to one may need to be reflected in the other.
158  * Rundown of the variables:
159  * vp - Pointer to the vnode
160  * counter - Partial name structure member to update in vopstats for counts
161  * bytecounter - Partial name structure member to update in vopstats for bytes
162  * bytesval - Value to update in vopstats for bytes
163  * fstype - Index into vsanchor_fstype[], same as index into vfssw[]
164  * vsp - Pointer to vopstats structure (either in vfs or vsanchor_fstype[i])
165  */
166 
167 #define	VOPSTATS_UPDATE(vp, counter) {					\
168 	vfs_t *vfsp = (vp)->v_vfsp;					\
169 	if (vfsp && vfsp->vfs_implp &&					\
170 	    (vfsp->vfs_flag & VFS_STATS) && (vp)->v_type != VBAD) {	\
171 		vopstats_t *vsp = &vfsp->vfs_vopstats;			\
172 		uint64_t *stataddr = &(vsp->n##counter.value.ui64);	\
173 		extern void __dtrace_probe___fsinfo_##counter(vnode_t *, \
174 		    size_t, uint64_t *);				\
175 		__dtrace_probe___fsinfo_##counter(vp, 0, stataddr);	\
176 		(*stataddr)++;						\
177 		if ((vsp = vfsp->vfs_fstypevsp) != NULL) {		\
178 			vsp->n##counter.value.ui64++;			\
179 		}							\
180 	}								\
181 }
182 
183 #define	VOPSTATS_UPDATE_IO(vp, counter, bytecounter, bytesval) {	\
184 	vfs_t *vfsp = (vp)->v_vfsp;					\
185 	if (vfsp && vfsp->vfs_implp &&					\
186 	    (vfsp->vfs_flag & VFS_STATS) && (vp)->v_type != VBAD) {	\
187 		vopstats_t *vsp = &vfsp->vfs_vopstats;			\
188 		uint64_t *stataddr = &(vsp->n##counter.value.ui64);	\
189 		extern void __dtrace_probe___fsinfo_##counter(vnode_t *, \
190 		    size_t, uint64_t *);				\
191 		__dtrace_probe___fsinfo_##counter(vp, bytesval, stataddr); \
192 		(*stataddr)++;						\
193 		vsp->bytecounter.value.ui64 += bytesval;		\
194 		if ((vsp = vfsp->vfs_fstypevsp) != NULL) {		\
195 			vsp->n##counter.value.ui64++;			\
196 			vsp->bytecounter.value.ui64 += bytesval;	\
197 		}							\
198 	}								\
199 }
200 
201 /*
202  * If the filesystem does not support XIDs map credential
203  * If the vfsp is NULL, perhaps we should also map?
204  */
205 #define	VOPXID_MAP_CR(vp, cr)	{					\
206 	vfs_t *vfsp = (vp)->v_vfsp;					\
207 	if (vfsp != NULL && (vfsp->vfs_flag & VFS_XID) == 0)		\
208 		cr = crgetmapped(cr);					\
209 	}
210 
211 /*
212  * Convert stat(2) formats to vnode types and vice versa.  (Knows about
213  * numerical order of S_IFMT and vnode types.)
214  */
215 enum vtype iftovt_tab[] = {
216 	VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
217 	VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VNON
218 };
219 
220 ushort_t vttoif_tab[] = {
221 	0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, S_IFIFO,
222 	S_IFDOOR, 0, S_IFSOCK, S_IFPORT, 0
223 };
224 
225 /*
226  * The system vnode cache.
227  */
228 
229 kmem_cache_t *vn_cache;
230 
231 
232 /*
233  * Vnode operations vector.
234  */
235 
236 static const fs_operation_trans_def_t vn_ops_table[] = {
237 	VOPNAME_OPEN, offsetof(struct vnodeops, vop_open),
238 	    fs_nosys, fs_nosys,
239 
240 	VOPNAME_CLOSE, offsetof(struct vnodeops, vop_close),
241 	    fs_nosys, fs_nosys,
242 
243 	VOPNAME_READ, offsetof(struct vnodeops, vop_read),
244 	    fs_nosys, fs_nosys,
245 
246 	VOPNAME_WRITE, offsetof(struct vnodeops, vop_write),
247 	    fs_nosys, fs_nosys,
248 
249 	VOPNAME_IOCTL, offsetof(struct vnodeops, vop_ioctl),
250 	    fs_nosys, fs_nosys,
251 
252 	VOPNAME_SETFL, offsetof(struct vnodeops, vop_setfl),
253 	    fs_setfl, fs_nosys,
254 
255 	VOPNAME_GETATTR, offsetof(struct vnodeops, vop_getattr),
256 	    fs_nosys, fs_nosys,
257 
258 	VOPNAME_SETATTR, offsetof(struct vnodeops, vop_setattr),
259 	    fs_nosys, fs_nosys,
260 
261 	VOPNAME_ACCESS, offsetof(struct vnodeops, vop_access),
262 	    fs_nosys, fs_nosys,
263 
264 	VOPNAME_LOOKUP, offsetof(struct vnodeops, vop_lookup),
265 	    fs_nosys, fs_nosys,
266 
267 	VOPNAME_CREATE, offsetof(struct vnodeops, vop_create),
268 	    fs_nosys, fs_nosys,
269 
270 	VOPNAME_REMOVE, offsetof(struct vnodeops, vop_remove),
271 	    fs_nosys, fs_nosys,
272 
273 	VOPNAME_LINK, offsetof(struct vnodeops, vop_link),
274 	    fs_nosys, fs_nosys,
275 
276 	VOPNAME_RENAME, offsetof(struct vnodeops, vop_rename),
277 	    fs_nosys, fs_nosys,
278 
279 	VOPNAME_MKDIR, offsetof(struct vnodeops, vop_mkdir),
280 	    fs_nosys, fs_nosys,
281 
282 	VOPNAME_RMDIR, offsetof(struct vnodeops, vop_rmdir),
283 	    fs_nosys, fs_nosys,
284 
285 	VOPNAME_READDIR, offsetof(struct vnodeops, vop_readdir),
286 	    fs_nosys, fs_nosys,
287 
288 	VOPNAME_SYMLINK, offsetof(struct vnodeops, vop_symlink),
289 	    fs_nosys, fs_nosys,
290 
291 	VOPNAME_READLINK, offsetof(struct vnodeops, vop_readlink),
292 	    fs_nosys, fs_nosys,
293 
294 	VOPNAME_FSYNC, offsetof(struct vnodeops, vop_fsync),
295 	    fs_nosys, fs_nosys,
296 
297 	VOPNAME_INACTIVE, offsetof(struct vnodeops, vop_inactive),
298 	    fs_nosys, fs_nosys,
299 
300 	VOPNAME_FID, offsetof(struct vnodeops, vop_fid),
301 	    fs_nosys, fs_nosys,
302 
303 	VOPNAME_RWLOCK, offsetof(struct vnodeops, vop_rwlock),
304 	    fs_rwlock, fs_rwlock,
305 
306 	VOPNAME_RWUNLOCK, offsetof(struct vnodeops, vop_rwunlock),
307 	    (fs_generic_func_p)(uintptr_t)fs_rwunlock,
308 	    (fs_generic_func_p)(uintptr_t)fs_rwunlock,	/* no errors allowed */
309 
310 	VOPNAME_SEEK, offsetof(struct vnodeops, vop_seek),
311 	    fs_nosys, fs_nosys,
312 
313 	VOPNAME_CMP, offsetof(struct vnodeops, vop_cmp),
314 	    fs_cmp, fs_cmp,		/* no errors allowed */
315 
316 	VOPNAME_FRLOCK, offsetof(struct vnodeops, vop_frlock),
317 	    fs_frlock, fs_nosys,
318 
319 	VOPNAME_SPACE, offsetof(struct vnodeops, vop_space),
320 	    fs_nosys, fs_nosys,
321 
322 	VOPNAME_REALVP, offsetof(struct vnodeops, vop_realvp),
323 	    fs_nosys, fs_nosys,
324 
325 	VOPNAME_GETPAGE, offsetof(struct vnodeops, vop_getpage),
326 	    fs_nosys, fs_nosys,
327 
328 	VOPNAME_PUTPAGE, offsetof(struct vnodeops, vop_putpage),
329 	    fs_nosys, fs_nosys,
330 
331 	VOPNAME_MAP, offsetof(struct vnodeops, vop_map),
332 	    (fs_generic_func_p) fs_nosys_map,
333 	    (fs_generic_func_p) fs_nosys_map,
334 
335 	VOPNAME_ADDMAP, offsetof(struct vnodeops, vop_addmap),
336 	    (fs_generic_func_p) fs_nosys_addmap,
337 	    (fs_generic_func_p) fs_nosys_addmap,
338 
339 	VOPNAME_DELMAP, offsetof(struct vnodeops, vop_delmap),
340 	    fs_nosys, fs_nosys,
341 
342 	VOPNAME_POLL, offsetof(struct vnodeops, vop_poll),
343 	    (fs_generic_func_p) fs_poll, (fs_generic_func_p) fs_nosys_poll,
344 
345 	VOPNAME_DUMP, offsetof(struct vnodeops, vop_dump),
346 	    fs_nosys, fs_nosys,
347 
348 	VOPNAME_PATHCONF, offsetof(struct vnodeops, vop_pathconf),
349 	    fs_pathconf, fs_nosys,
350 
351 	VOPNAME_PAGEIO, offsetof(struct vnodeops, vop_pageio),
352 	    fs_nosys, fs_nosys,
353 
354 	VOPNAME_DUMPCTL, offsetof(struct vnodeops, vop_dumpctl),
355 	    fs_nosys, fs_nosys,
356 
357 	VOPNAME_DISPOSE, offsetof(struct vnodeops, vop_dispose),
358 	    (fs_generic_func_p)(uintptr_t)fs_dispose,
359 	    (fs_generic_func_p)(uintptr_t)fs_nodispose,
360 
361 	VOPNAME_SETSECATTR, offsetof(struct vnodeops, vop_setsecattr),
362 	    fs_nosys, fs_nosys,
363 
364 	VOPNAME_GETSECATTR, offsetof(struct vnodeops, vop_getsecattr),
365 	    fs_fab_acl, fs_nosys,
366 
367 	VOPNAME_SHRLOCK, offsetof(struct vnodeops, vop_shrlock),
368 	    fs_shrlock, fs_nosys,
369 
370 	VOPNAME_VNEVENT, offsetof(struct vnodeops, vop_vnevent),
371 	    (fs_generic_func_p) fs_vnevent_nosupport,
372 	    (fs_generic_func_p) fs_vnevent_nosupport,
373 
374 	VOPNAME_REQZCBUF, offsetof(struct vnodeops, vop_reqzcbuf),
375 	    fs_nosys, fs_nosys,
376 
377 	VOPNAME_RETZCBUF, offsetof(struct vnodeops, vop_retzcbuf),
378 	    fs_nosys, fs_nosys,
379 
380 	NULL, 0, NULL, NULL
381 };
382 
383 /* Extensible attribute (xva) routines. */
384 
385 /*
386  * Zero out the structure, set the size of the requested/returned bitmaps,
387  * set AT_XVATTR in the embedded vattr_t's va_mask, and set up the pointer
388  * to the returned attributes array.
389  */
390 void
391 xva_init(xvattr_t *xvap)
392 {
393 	bzero(xvap, sizeof (xvattr_t));
394 	xvap->xva_mapsize = XVA_MAPSIZE;
395 	xvap->xva_magic = XVA_MAGIC;
396 	xvap->xva_vattr.va_mask = AT_XVATTR;
397 	xvap->xva_rtnattrmapp = &(xvap->xva_rtnattrmap)[0];
398 }
399 
400 /*
401  * If AT_XVATTR is set, returns a pointer to the embedded xoptattr_t
402  * structure.  Otherwise, returns NULL.
403  */
404 xoptattr_t *
405 xva_getxoptattr(xvattr_t *xvap)
406 {
407 	xoptattr_t *xoap = NULL;
408 	if (xvap->xva_vattr.va_mask & AT_XVATTR)
409 		xoap = &xvap->xva_xoptattrs;
410 	return (xoap);
411 }
412 
413 /*
414  * Used by the AVL routines to compare two vsk_anchor_t structures in the tree.
415  * We use the f_fsid reported by VFS_STATVFS() since we use that for the
416  * kstat name.
417  */
418 static int
419 vska_compar(const void *n1, const void *n2)
420 {
421 	int ret;
422 	ulong_t p1 = ((vsk_anchor_t *)n1)->vsk_fsid;
423 	ulong_t p2 = ((vsk_anchor_t *)n2)->vsk_fsid;
424 
425 	if (p1 < p2) {
426 		ret = -1;
427 	} else if (p1 > p2) {
428 		ret = 1;
429 	} else {
430 		ret = 0;
431 	}
432 
433 	return (ret);
434 }
435 
436 /*
437  * Used to create a single template which will be bcopy()ed to a newly
438  * allocated vsanchor_combo_t structure in new_vsanchor(), below.
439  */
440 static vopstats_t *
441 create_vopstats_template()
442 {
443 	vopstats_t		*vsp;
444 
445 	vsp = kmem_alloc(sizeof (vopstats_t), KM_SLEEP);
446 	bzero(vsp, sizeof (*vsp));	/* Start fresh */
447 
448 	/* VOP_OPEN */
449 	kstat_named_init(&vsp->nopen, "nopen", KSTAT_DATA_UINT64);
450 	/* VOP_CLOSE */
451 	kstat_named_init(&vsp->nclose, "nclose", KSTAT_DATA_UINT64);
452 	/* VOP_READ I/O */
453 	kstat_named_init(&vsp->nread, "nread", KSTAT_DATA_UINT64);
454 	kstat_named_init(&vsp->read_bytes, "read_bytes", KSTAT_DATA_UINT64);
455 	/* VOP_WRITE I/O */
456 	kstat_named_init(&vsp->nwrite, "nwrite", KSTAT_DATA_UINT64);
457 	kstat_named_init(&vsp->write_bytes, "write_bytes", KSTAT_DATA_UINT64);
458 	/* VOP_IOCTL */
459 	kstat_named_init(&vsp->nioctl, "nioctl", KSTAT_DATA_UINT64);
460 	/* VOP_SETFL */
461 	kstat_named_init(&vsp->nsetfl, "nsetfl", KSTAT_DATA_UINT64);
462 	/* VOP_GETATTR */
463 	kstat_named_init(&vsp->ngetattr, "ngetattr", KSTAT_DATA_UINT64);
464 	/* VOP_SETATTR */
465 	kstat_named_init(&vsp->nsetattr, "nsetattr", KSTAT_DATA_UINT64);
466 	/* VOP_ACCESS */
467 	kstat_named_init(&vsp->naccess, "naccess", KSTAT_DATA_UINT64);
468 	/* VOP_LOOKUP */
469 	kstat_named_init(&vsp->nlookup, "nlookup", KSTAT_DATA_UINT64);
470 	/* VOP_CREATE */
471 	kstat_named_init(&vsp->ncreate, "ncreate", KSTAT_DATA_UINT64);
472 	/* VOP_REMOVE */
473 	kstat_named_init(&vsp->nremove, "nremove", KSTAT_DATA_UINT64);
474 	/* VOP_LINK */
475 	kstat_named_init(&vsp->nlink, "nlink", KSTAT_DATA_UINT64);
476 	/* VOP_RENAME */
477 	kstat_named_init(&vsp->nrename, "nrename", KSTAT_DATA_UINT64);
478 	/* VOP_MKDIR */
479 	kstat_named_init(&vsp->nmkdir, "nmkdir", KSTAT_DATA_UINT64);
480 	/* VOP_RMDIR */
481 	kstat_named_init(&vsp->nrmdir, "nrmdir", KSTAT_DATA_UINT64);
482 	/* VOP_READDIR I/O */
483 	kstat_named_init(&vsp->nreaddir, "nreaddir", KSTAT_DATA_UINT64);
484 	kstat_named_init(&vsp->readdir_bytes, "readdir_bytes",
485 	    KSTAT_DATA_UINT64);
486 	/* VOP_SYMLINK */
487 	kstat_named_init(&vsp->nsymlink, "nsymlink", KSTAT_DATA_UINT64);
488 	/* VOP_READLINK */
489 	kstat_named_init(&vsp->nreadlink, "nreadlink", KSTAT_DATA_UINT64);
490 	/* VOP_FSYNC */
491 	kstat_named_init(&vsp->nfsync, "nfsync", KSTAT_DATA_UINT64);
492 	/* VOP_INACTIVE */
493 	kstat_named_init(&vsp->ninactive, "ninactive", KSTAT_DATA_UINT64);
494 	/* VOP_FID */
495 	kstat_named_init(&vsp->nfid, "nfid", KSTAT_DATA_UINT64);
496 	/* VOP_RWLOCK */
497 	kstat_named_init(&vsp->nrwlock, "nrwlock", KSTAT_DATA_UINT64);
498 	/* VOP_RWUNLOCK */
499 	kstat_named_init(&vsp->nrwunlock, "nrwunlock", KSTAT_DATA_UINT64);
500 	/* VOP_SEEK */
501 	kstat_named_init(&vsp->nseek, "nseek", KSTAT_DATA_UINT64);
502 	/* VOP_CMP */
503 	kstat_named_init(&vsp->ncmp, "ncmp", KSTAT_DATA_UINT64);
504 	/* VOP_FRLOCK */
505 	kstat_named_init(&vsp->nfrlock, "nfrlock", KSTAT_DATA_UINT64);
506 	/* VOP_SPACE */
507 	kstat_named_init(&vsp->nspace, "nspace", KSTAT_DATA_UINT64);
508 	/* VOP_REALVP */
509 	kstat_named_init(&vsp->nrealvp, "nrealvp", KSTAT_DATA_UINT64);
510 	/* VOP_GETPAGE */
511 	kstat_named_init(&vsp->ngetpage, "ngetpage", KSTAT_DATA_UINT64);
512 	/* VOP_PUTPAGE */
513 	kstat_named_init(&vsp->nputpage, "nputpage", KSTAT_DATA_UINT64);
514 	/* VOP_MAP */
515 	kstat_named_init(&vsp->nmap, "nmap", KSTAT_DATA_UINT64);
516 	/* VOP_ADDMAP */
517 	kstat_named_init(&vsp->naddmap, "naddmap", KSTAT_DATA_UINT64);
518 	/* VOP_DELMAP */
519 	kstat_named_init(&vsp->ndelmap, "ndelmap", KSTAT_DATA_UINT64);
520 	/* VOP_POLL */
521 	kstat_named_init(&vsp->npoll, "npoll", KSTAT_DATA_UINT64);
522 	/* VOP_DUMP */
523 	kstat_named_init(&vsp->ndump, "ndump", KSTAT_DATA_UINT64);
524 	/* VOP_PATHCONF */
525 	kstat_named_init(&vsp->npathconf, "npathconf", KSTAT_DATA_UINT64);
526 	/* VOP_PAGEIO */
527 	kstat_named_init(&vsp->npageio, "npageio", KSTAT_DATA_UINT64);
528 	/* VOP_DUMPCTL */
529 	kstat_named_init(&vsp->ndumpctl, "ndumpctl", KSTAT_DATA_UINT64);
530 	/* VOP_DISPOSE */
531 	kstat_named_init(&vsp->ndispose, "ndispose", KSTAT_DATA_UINT64);
532 	/* VOP_SETSECATTR */
533 	kstat_named_init(&vsp->nsetsecattr, "nsetsecattr", KSTAT_DATA_UINT64);
534 	/* VOP_GETSECATTR */
535 	kstat_named_init(&vsp->ngetsecattr, "ngetsecattr", KSTAT_DATA_UINT64);
536 	/* VOP_SHRLOCK */
537 	kstat_named_init(&vsp->nshrlock, "nshrlock", KSTAT_DATA_UINT64);
538 	/* VOP_VNEVENT */
539 	kstat_named_init(&vsp->nvnevent, "nvnevent", KSTAT_DATA_UINT64);
540 	/* VOP_REQZCBUF */
541 	kstat_named_init(&vsp->nreqzcbuf, "nreqzcbuf", KSTAT_DATA_UINT64);
542 	/* VOP_RETZCBUF */
543 	kstat_named_init(&vsp->nretzcbuf, "nretzcbuf", KSTAT_DATA_UINT64);
544 
545 	return (vsp);
546 }
547 
548 /*
549  * Creates a kstat structure associated with a vopstats structure.
550  */
551 kstat_t *
552 new_vskstat(char *ksname, vopstats_t *vsp)
553 {
554 	kstat_t		*ksp;
555 
556 	if (!vopstats_enabled) {
557 		return (NULL);
558 	}
559 
560 	ksp = kstat_create("unix", 0, ksname, "misc", KSTAT_TYPE_NAMED,
561 	    sizeof (vopstats_t)/sizeof (kstat_named_t),
562 	    KSTAT_FLAG_VIRTUAL|KSTAT_FLAG_WRITABLE);
563 	if (ksp) {
564 		ksp->ks_data = vsp;
565 		kstat_install(ksp);
566 	}
567 
568 	return (ksp);
569 }
570 
571 /*
572  * Called from vfsinit() to initialize the support mechanisms for vopstats
573  */
574 void
575 vopstats_startup()
576 {
577 	if (!vopstats_enabled)
578 		return;
579 
580 	/*
581 	 * Creates the AVL tree which holds per-vfs vopstat anchors.  This
582 	 * is necessary since we need to check if a kstat exists before we
583 	 * attempt to create it.  Also, initialize its lock.
584 	 */
585 	avl_create(&vskstat_tree, vska_compar, sizeof (vsk_anchor_t),
586 	    offsetof(vsk_anchor_t, vsk_node));
587 	mutex_init(&vskstat_tree_lock, NULL, MUTEX_DEFAULT, NULL);
588 
589 	vsk_anchor_cache = kmem_cache_create("vsk_anchor_cache",
590 	    sizeof (vsk_anchor_t), sizeof (uintptr_t), NULL, NULL, NULL,
591 	    NULL, NULL, 0);
592 
593 	/*
594 	 * Set up the array of pointers for the vopstats-by-FS-type.
595 	 * The entries will be allocated/initialized as each file system
596 	 * goes through modload/mod_installfs.
597 	 */
598 	vopstats_fstype = (vopstats_t **)kmem_zalloc(
599 	    (sizeof (vopstats_t *) * nfstype), KM_SLEEP);
600 
601 	/* Set up the global vopstats initialization template */
602 	vs_templatep = create_vopstats_template();
603 }
604 
605 /*
606  * We need to have the all of the counters zeroed.
607  * The initialization of the vopstats_t includes on the order of
608  * 50 calls to kstat_named_init().  Rather that do that on every call,
609  * we do it once in a template (vs_templatep) then bcopy it over.
610  */
611 void
612 initialize_vopstats(vopstats_t *vsp)
613 {
614 	if (vsp == NULL)
615 		return;
616 
617 	bcopy(vs_templatep, vsp, sizeof (vopstats_t));
618 }
619 
620 /*
621  * If possible, determine which vopstats by fstype to use and
622  * return a pointer to the caller.
623  */
624 vopstats_t *
625 get_fstype_vopstats(vfs_t *vfsp, struct vfssw *vswp)
626 {
627 	int		fstype = 0;	/* Index into vfssw[] */
628 	vopstats_t	*vsp = NULL;
629 
630 	if (vfsp == NULL || (vfsp->vfs_flag & VFS_STATS) == 0 ||
631 	    !vopstats_enabled)
632 		return (NULL);
633 	/*
634 	 * Set up the fstype.  We go to so much trouble because all versions
635 	 * of NFS use the same fstype in their vfs even though they have
636 	 * distinct entries in the vfssw[] table.
637 	 * NOTE: A special vfs (e.g., EIO_vfs) may not have an entry.
638 	 */
639 	if (vswp) {
640 		fstype = vswp - vfssw;	/* Gets us the index */
641 	} else {
642 		fstype = vfsp->vfs_fstype;
643 	}
644 
645 	/*
646 	 * Point to the per-fstype vopstats. The only valid values are
647 	 * non-zero positive values less than the number of vfssw[] table
648 	 * entries.
649 	 */
650 	if (fstype > 0 && fstype < nfstype) {
651 		vsp = vopstats_fstype[fstype];
652 	}
653 
654 	return (vsp);
655 }
656 
657 /*
658  * Generate a kstat name, create the kstat structure, and allocate a
659  * vsk_anchor_t to hold it together.  Return the pointer to the vsk_anchor_t
660  * to the caller.  This must only be called from a mount.
661  */
662 vsk_anchor_t *
663 get_vskstat_anchor(vfs_t *vfsp)
664 {
665 	char		kstatstr[KSTAT_STRLEN]; /* kstat name for vopstats */
666 	statvfs64_t	statvfsbuf;		/* Needed to find f_fsid */
667 	vsk_anchor_t	*vskp = NULL;		/* vfs <--> kstat anchor */
668 	kstat_t		*ksp;			/* Ptr to new kstat */
669 	avl_index_t	where;			/* Location in the AVL tree */
670 
671 	if (vfsp == NULL || vfsp->vfs_implp == NULL ||
672 	    (vfsp->vfs_flag & VFS_STATS) == 0 || !vopstats_enabled)
673 		return (NULL);
674 
675 	/* Need to get the fsid to build a kstat name */
676 	if (VFS_STATVFS(vfsp, &statvfsbuf) == 0) {
677 		/* Create a name for our kstats based on fsid */
678 		(void) snprintf(kstatstr, KSTAT_STRLEN, "%s%lx",
679 		    VOPSTATS_STR, statvfsbuf.f_fsid);
680 
681 		/* Allocate and initialize the vsk_anchor_t */
682 		vskp = kmem_cache_alloc(vsk_anchor_cache, KM_SLEEP);
683 		bzero(vskp, sizeof (*vskp));
684 		vskp->vsk_fsid = statvfsbuf.f_fsid;
685 
686 		mutex_enter(&vskstat_tree_lock);
687 		if (avl_find(&vskstat_tree, vskp, &where) == NULL) {
688 			avl_insert(&vskstat_tree, vskp, where);
689 			mutex_exit(&vskstat_tree_lock);
690 
691 			/*
692 			 * Now that we've got the anchor in the AVL
693 			 * tree, we can create the kstat.
694 			 */
695 			ksp = new_vskstat(kstatstr, &vfsp->vfs_vopstats);
696 			if (ksp) {
697 				vskp->vsk_ksp = ksp;
698 			}
699 		} else {
700 			/* Oops, found one! Release memory and lock. */
701 			mutex_exit(&vskstat_tree_lock);
702 			kmem_cache_free(vsk_anchor_cache, vskp);
703 			vskp = NULL;
704 		}
705 	}
706 	return (vskp);
707 }
708 
709 /*
710  * We're in the process of tearing down the vfs and need to cleanup
711  * the data structures associated with the vopstats. Must only be called
712  * from dounmount().
713  */
714 void
715 teardown_vopstats(vfs_t *vfsp)
716 {
717 	vsk_anchor_t	*vskap;
718 	avl_index_t	where;
719 
720 	if (vfsp == NULL || vfsp->vfs_implp == NULL ||
721 	    (vfsp->vfs_flag & VFS_STATS) == 0 || !vopstats_enabled)
722 		return;
723 
724 	/* This is a safe check since VFS_STATS must be set (see above) */
725 	if ((vskap = vfsp->vfs_vskap) == NULL)
726 		return;
727 
728 	/* Whack the pointer right away */
729 	vfsp->vfs_vskap = NULL;
730 
731 	/* Lock the tree, remove the node, and delete the kstat */
732 	mutex_enter(&vskstat_tree_lock);
733 	if (avl_find(&vskstat_tree, vskap, &where)) {
734 		avl_remove(&vskstat_tree, vskap);
735 	}
736 
737 	if (vskap->vsk_ksp) {
738 		kstat_delete(vskap->vsk_ksp);
739 	}
740 	mutex_exit(&vskstat_tree_lock);
741 
742 	kmem_cache_free(vsk_anchor_cache, vskap);
743 }
744 
745 /*
746  * Read or write a vnode.  Called from kernel code.
747  */
748 int
749 vn_rdwr(
750 	enum uio_rw rw,
751 	struct vnode *vp,
752 	caddr_t base,
753 	ssize_t len,
754 	offset_t offset,
755 	enum uio_seg seg,
756 	int ioflag,
757 	rlim64_t ulimit,	/* meaningful only if rw is UIO_WRITE */
758 	cred_t *cr,
759 	ssize_t *residp)
760 {
761 	struct uio uio;
762 	struct iovec iov;
763 	int error;
764 	int in_crit = 0;
765 
766 	if (rw == UIO_WRITE && ISROFILE(vp))
767 		return (EROFS);
768 
769 	if (len < 0)
770 		return (EIO);
771 
772 	VOPXID_MAP_CR(vp, cr);
773 
774 	iov.iov_base = base;
775 	iov.iov_len = len;
776 	uio.uio_iov = &iov;
777 	uio.uio_iovcnt = 1;
778 	uio.uio_loffset = offset;
779 	uio.uio_segflg = (short)seg;
780 	uio.uio_resid = len;
781 	uio.uio_llimit = ulimit;
782 
783 	/*
784 	 * We have to enter the critical region before calling VOP_RWLOCK
785 	 * to avoid a deadlock with ufs.
786 	 */
787 	if (nbl_need_check(vp)) {
788 		int svmand;
789 
790 		nbl_start_crit(vp, RW_READER);
791 		in_crit = 1;
792 		error = nbl_svmand(vp, cr, &svmand);
793 		if (error != 0)
794 			goto done;
795 		if (nbl_conflict(vp, rw == UIO_WRITE ? NBL_WRITE : NBL_READ,
796 		    uio.uio_offset, uio.uio_resid, svmand, NULL)) {
797 			error = EACCES;
798 			goto done;
799 		}
800 	}
801 
802 	(void) VOP_RWLOCK(vp,
803 	    rw == UIO_WRITE ? V_WRITELOCK_TRUE : V_WRITELOCK_FALSE, NULL);
804 	if (rw == UIO_WRITE) {
805 		uio.uio_fmode = FWRITE;
806 		uio.uio_extflg = UIO_COPY_DEFAULT;
807 		error = VOP_WRITE(vp, &uio, ioflag, cr, NULL);
808 	} else {
809 		uio.uio_fmode = FREAD;
810 		uio.uio_extflg = UIO_COPY_CACHED;
811 		error = VOP_READ(vp, &uio, ioflag, cr, NULL);
812 	}
813 	VOP_RWUNLOCK(vp,
814 	    rw == UIO_WRITE ? V_WRITELOCK_TRUE : V_WRITELOCK_FALSE, NULL);
815 	if (residp)
816 		*residp = uio.uio_resid;
817 	else if (uio.uio_resid)
818 		error = EIO;
819 
820 done:
821 	if (in_crit)
822 		nbl_end_crit(vp);
823 	return (error);
824 }
825 
826 /*
827  * Release a vnode.  Call VOP_INACTIVE on last reference or
828  * decrement reference count.
829  *
830  * To avoid race conditions, the v_count is left at 1 for
831  * the call to VOP_INACTIVE. This prevents another thread
832  * from reclaiming and releasing the vnode *before* the
833  * VOP_INACTIVE routine has a chance to destroy the vnode.
834  * We can't have more than 1 thread calling VOP_INACTIVE
835  * on a vnode.
836  */
837 void
838 vn_rele(vnode_t *vp)
839 {
840 	VERIFY(vp->v_count > 0);
841 	mutex_enter(&vp->v_lock);
842 	if (vp->v_count == 1) {
843 		mutex_exit(&vp->v_lock);
844 		VOP_INACTIVE(vp, CRED(), NULL);
845 		return;
846 	}
847 	VN_RELE_LOCKED(vp);
848 	mutex_exit(&vp->v_lock);
849 }
850 
851 /*
852  * Release a vnode referenced by the DNLC. Multiple DNLC references are treated
853  * as a single reference, so v_count is not decremented until the last DNLC hold
854  * is released. This makes it possible to distinguish vnodes that are referenced
855  * only by the DNLC.
856  */
857 void
858 vn_rele_dnlc(vnode_t *vp)
859 {
860 	VERIFY((vp->v_count > 0) && (vp->v_count_dnlc > 0));
861 	mutex_enter(&vp->v_lock);
862 	if (--vp->v_count_dnlc == 0) {
863 		if (vp->v_count == 1) {
864 			mutex_exit(&vp->v_lock);
865 			VOP_INACTIVE(vp, CRED(), NULL);
866 			return;
867 		}
868 		VN_RELE_LOCKED(vp);
869 	}
870 	mutex_exit(&vp->v_lock);
871 }
872 
873 /*
874  * Like vn_rele() except that it clears v_stream under v_lock.
875  * This is used by sockfs when it dismantles the association between
876  * the sockfs node and the vnode in the underlying file system.
877  * v_lock has to be held to prevent a thread coming through the lookupname
878  * path from accessing a stream head that is going away.
879  */
880 void
881 vn_rele_stream(vnode_t *vp)
882 {
883 	VERIFY(vp->v_count > 0);
884 	mutex_enter(&vp->v_lock);
885 	vp->v_stream = NULL;
886 	if (vp->v_count == 1) {
887 		mutex_exit(&vp->v_lock);
888 		VOP_INACTIVE(vp, CRED(), NULL);
889 		return;
890 	}
891 	VN_RELE_LOCKED(vp);
892 	mutex_exit(&vp->v_lock);
893 }
894 
895 static void
896 vn_rele_inactive(vnode_t *vp)
897 {
898 	VOP_INACTIVE(vp, CRED(), NULL);
899 }
900 
901 /*
902  * Like vn_rele() except if we are going to call VOP_INACTIVE() then do it
903  * asynchronously using a taskq. This can avoid deadlocks caused by re-entering
904  * the file system as a result of releasing the vnode. Note, file systems
905  * already have to handle the race where the vnode is incremented before the
906  * inactive routine is called and does its locking.
907  *
908  * Warning: Excessive use of this routine can lead to performance problems.
909  * This is because taskqs throttle back allocation if too many are created.
910  */
911 void
912 vn_rele_async(vnode_t *vp, taskq_t *taskq)
913 {
914 	VERIFY(vp->v_count > 0);
915 	mutex_enter(&vp->v_lock);
916 	if (vp->v_count == 1) {
917 		mutex_exit(&vp->v_lock);
918 		VERIFY(taskq_dispatch(taskq, (task_func_t *)vn_rele_inactive,
919 		    vp, TQ_SLEEP) != TASKQID_INVALID);
920 		return;
921 	}
922 	VN_RELE_LOCKED(vp);
923 	mutex_exit(&vp->v_lock);
924 }
925 
926 int
927 vn_open(
928 	char *pnamep,
929 	enum uio_seg seg,
930 	int filemode,
931 	int createmode,
932 	struct vnode **vpp,
933 	enum create crwhy,
934 	mode_t umask)
935 {
936 	return (vn_openat(pnamep, seg, filemode, createmode, vpp, crwhy,
937 	    umask, NULL, -1));
938 }
939 
940 
941 /*
942  * Open/create a vnode.
943  * This may be callable by the kernel, the only known use
944  * of user context being that the current user credentials
945  * are used for permissions.  crwhy is defined iff filemode & FCREAT.
946  */
947 int
948 vn_openat(
949 	char *pnamep,
950 	enum uio_seg seg,
951 	int filemode,
952 	int createmode,
953 	struct vnode **vpp,
954 	enum create crwhy,
955 	mode_t umask,
956 	struct vnode *startvp,
957 	int fd)
958 {
959 	struct vnode *vp;
960 	int mode;
961 	int accessflags;
962 	int error;
963 	int in_crit = 0;
964 	int open_done = 0;
965 	int shrlock_done = 0;
966 	struct vattr vattr;
967 	enum symfollow follow;
968 	int estale_retry = 0;
969 	struct shrlock shr;
970 	struct shr_locowner shr_own;
971 	boolean_t create;
972 
973 	mode = 0;
974 	accessflags = 0;
975 	if (filemode & FREAD)
976 		mode |= VREAD;
977 	if (filemode & (FWRITE|FTRUNC))
978 		mode |= VWRITE;
979 	if (filemode & (FSEARCH|FEXEC|FXATTRDIROPEN))
980 		mode |= VEXEC;
981 
982 	/* symlink interpretation */
983 	if (filemode & FNOFOLLOW)
984 		follow = NO_FOLLOW;
985 	else
986 		follow = FOLLOW;
987 
988 	if (filemode & FAPPEND)
989 		accessflags |= V_APPEND;
990 
991 	/*
992 	 * We need to handle the case of FCREAT | FDIRECTORY and the case of
993 	 * FEXCL. If all three are specified, then we always fail because we
994 	 * cannot create a directory through this interface and FEXCL says we
995 	 * need to fail the request if we can't create it. If, however, only
996 	 * FCREAT | FDIRECTORY are specified, then we can treat this as the case
997 	 * of opening a file that already exists. If it exists, we can do
998 	 * something and if not, we fail. Effectively FCREAT | FDIRECTORY is
999 	 * treated as FDIRECTORY.
1000 	 */
1001 	if ((filemode & (FCREAT | FDIRECTORY | FEXCL)) ==
1002 	    (FCREAT | FDIRECTORY | FEXCL)) {
1003 		return (EINVAL);
1004 	}
1005 
1006 	if ((filemode & (FCREAT | FDIRECTORY)) == (FCREAT | FDIRECTORY)) {
1007 		create = B_FALSE;
1008 	} else if ((filemode & FCREAT) != 0) {
1009 		create = B_TRUE;
1010 	} else {
1011 		create = B_FALSE;
1012 	}
1013 
1014 top:
1015 	if (create) {
1016 		enum vcexcl excl;
1017 
1018 		/*
1019 		 * Wish to create a file.
1020 		 */
1021 		vattr.va_type = VREG;
1022 		vattr.va_mode = createmode;
1023 		vattr.va_mask = AT_TYPE|AT_MODE;
1024 		if (filemode & FTRUNC) {
1025 			vattr.va_size = 0;
1026 			vattr.va_mask |= AT_SIZE;
1027 		}
1028 		if (filemode & FEXCL)
1029 			excl = EXCL;
1030 		else
1031 			excl = NONEXCL;
1032 
1033 		if (error =
1034 		    vn_createat(pnamep, seg, &vattr, excl, mode, &vp, crwhy,
1035 		    (filemode & ~(FTRUNC|FEXCL)), umask, startvp))
1036 			return (error);
1037 	} else {
1038 		/*
1039 		 * Wish to open a file.  Just look it up.
1040 		 */
1041 		if (error = lookupnameat(pnamep, seg, follow,
1042 		    NULLVPP, &vp, startvp)) {
1043 			if ((error == ESTALE) &&
1044 			    fs_need_estale_retry(estale_retry++))
1045 				goto top;
1046 			return (error);
1047 		}
1048 
1049 		/*
1050 		 * Get the attributes to check whether file is large.
1051 		 * We do this only if the FOFFMAX flag is not set and
1052 		 * only for regular files.
1053 		 */
1054 
1055 		if (!(filemode & FOFFMAX) && (vp->v_type == VREG)) {
1056 			vattr.va_mask = AT_SIZE;
1057 			if ((error = VOP_GETATTR(vp, &vattr, 0,
1058 			    CRED(), NULL))) {
1059 				goto out;
1060 			}
1061 			if (vattr.va_size > (u_offset_t)MAXOFF32_T) {
1062 				/*
1063 				 * Large File API - regular open fails
1064 				 * if FOFFMAX flag is set in file mode
1065 				 */
1066 				error = EOVERFLOW;
1067 				goto out;
1068 			}
1069 		}
1070 		/*
1071 		 * Can't write directories, active texts, or
1072 		 * read-only filesystems.  Can't truncate files
1073 		 * on which mandatory locking is in effect.
1074 		 */
1075 		if (filemode & (FWRITE|FTRUNC)) {
1076 			/*
1077 			 * Allow writable directory if VDIROPEN flag is set.
1078 			 */
1079 			if (vp->v_type == VDIR && !(vp->v_flag & VDIROPEN)) {
1080 				error = EISDIR;
1081 				goto out;
1082 			}
1083 			if (ISROFILE(vp)) {
1084 				error = EROFS;
1085 				goto out;
1086 			}
1087 			/*
1088 			 * Can't truncate files on which
1089 			 * sysv mandatory locking is in effect.
1090 			 */
1091 			if (filemode & FTRUNC) {
1092 				vnode_t *rvp;
1093 
1094 				if (VOP_REALVP(vp, &rvp, NULL) != 0)
1095 					rvp = vp;
1096 				if (rvp->v_filocks != NULL) {
1097 					vattr.va_mask = AT_MODE;
1098 					if ((error = VOP_GETATTR(vp,
1099 					    &vattr, 0, CRED(), NULL)) == 0 &&
1100 					    MANDLOCK(vp, vattr.va_mode))
1101 						error = EAGAIN;
1102 				}
1103 			}
1104 			if (error)
1105 				goto out;
1106 		}
1107 		/*
1108 		 * Check permissions.
1109 		 */
1110 		if (error = VOP_ACCESS(vp, mode, accessflags, CRED(), NULL))
1111 			goto out;
1112 
1113 		/*
1114 		 * Require FSEARCH and FDIRECTORY to return a directory. Require
1115 		 * FEXEC to return a regular file.
1116 		 */
1117 		if ((filemode & (FSEARCH|FDIRECTORY)) != 0 &&
1118 		    vp->v_type != VDIR) {
1119 			error = ENOTDIR;
1120 			goto out;
1121 		}
1122 		if ((filemode & FEXEC) && vp->v_type != VREG) {
1123 			error = ENOEXEC;	/* XXX: error code? */
1124 			goto out;
1125 		}
1126 	}
1127 
1128 	/*
1129 	 * Do remaining checks for FNOFOLLOW and FNOLINKS.
1130 	 */
1131 	if ((filemode & FNOFOLLOW) && vp->v_type == VLNK) {
1132 		error = ELOOP;
1133 		goto out;
1134 	}
1135 	if (filemode & FNOLINKS) {
1136 		vattr.va_mask = AT_NLINK;
1137 		if ((error = VOP_GETATTR(vp, &vattr, 0, CRED(), NULL))) {
1138 			goto out;
1139 		}
1140 		if (vattr.va_nlink != 1) {
1141 			error = EMLINK;
1142 			goto out;
1143 		}
1144 	}
1145 
1146 	/*
1147 	 * Opening a socket corresponding to the AF_UNIX pathname
1148 	 * in the filesystem name space is not supported.
1149 	 * However, VSOCK nodes in namefs are supported in order
1150 	 * to make fattach work for sockets.
1151 	 *
1152 	 * XXX This uses VOP_REALVP to distinguish between
1153 	 * an unopened namefs node (where VOP_REALVP returns a
1154 	 * different VSOCK vnode) and a VSOCK created by vn_create
1155 	 * in some file system (where VOP_REALVP would never return
1156 	 * a different vnode).
1157 	 */
1158 	if (vp->v_type == VSOCK) {
1159 		struct vnode *nvp;
1160 
1161 		error = VOP_REALVP(vp, &nvp, NULL);
1162 		if (error != 0 || nvp == NULL || nvp == vp ||
1163 		    nvp->v_type != VSOCK) {
1164 			error = EOPNOTSUPP;
1165 			goto out;
1166 		}
1167 	}
1168 
1169 	if ((vp->v_type == VREG) && nbl_need_check(vp)) {
1170 		/* get share reservation */
1171 		shr.s_access = 0;
1172 		if (filemode & FWRITE)
1173 			shr.s_access |= F_WRACC;
1174 		if (filemode & FREAD)
1175 			shr.s_access |= F_RDACC;
1176 		shr.s_deny = 0;
1177 		shr.s_sysid = 0;
1178 		shr.s_pid = ttoproc(curthread)->p_pid;
1179 		shr_own.sl_pid = shr.s_pid;
1180 		shr_own.sl_id = fd;
1181 		shr.s_own_len = sizeof (shr_own);
1182 		shr.s_owner = (caddr_t)&shr_own;
1183 		error = VOP_SHRLOCK(vp, F_SHARE_NBMAND, &shr, filemode, CRED(),
1184 		    NULL);
1185 		if (error)
1186 			goto out;
1187 		shrlock_done = 1;
1188 
1189 		/* nbmand conflict check if truncating file */
1190 		if ((filemode & FTRUNC) && !(filemode & FCREAT)) {
1191 			nbl_start_crit(vp, RW_READER);
1192 			in_crit = 1;
1193 
1194 			vattr.va_mask = AT_SIZE;
1195 			if (error = VOP_GETATTR(vp, &vattr, 0, CRED(), NULL))
1196 				goto out;
1197 			if (nbl_conflict(vp, NBL_WRITE, 0, vattr.va_size, 0,
1198 			    NULL)) {
1199 				error = EACCES;
1200 				goto out;
1201 			}
1202 		}
1203 	}
1204 
1205 	/*
1206 	 * Do opening protocol.
1207 	 */
1208 	error = VOP_OPEN(&vp, filemode, CRED(), NULL);
1209 	if (error)
1210 		goto out;
1211 	open_done = 1;
1212 
1213 	/*
1214 	 * Truncate if required.
1215 	 */
1216 	if ((filemode & FTRUNC) && !(filemode & FCREAT)) {
1217 		vattr.va_size = 0;
1218 		vattr.va_mask = AT_SIZE;
1219 		if ((error = VOP_SETATTR(vp, &vattr, 0, CRED(), NULL)) != 0)
1220 			goto out;
1221 	}
1222 
1223 	/*
1224 	 * Turn on directio, if requested.
1225 	 */
1226 	if (filemode & FDIRECT) {
1227 		if ((error = VOP_IOCTL(vp, _FIODIRECTIO, DIRECTIO_ON, 0,
1228 		    CRED(), NULL, NULL)) != 0) {
1229 			/*
1230 			 * On Linux, O_DIRECT returns EINVAL when the file
1231 			 * system does not support directio, so we'll do the
1232 			 * same.
1233 			 */
1234 			error = EINVAL;
1235 			goto out;
1236 		}
1237 	}
1238 out:
1239 	ASSERT(vp->v_count > 0);
1240 
1241 	if (in_crit) {
1242 		nbl_end_crit(vp);
1243 		in_crit = 0;
1244 	}
1245 	if (error) {
1246 		if (open_done) {
1247 			(void) VOP_CLOSE(vp, filemode, 1, (offset_t)0, CRED(),
1248 			    NULL);
1249 			open_done = 0;
1250 			shrlock_done = 0;
1251 		}
1252 		if (shrlock_done) {
1253 			(void) VOP_SHRLOCK(vp, F_UNSHARE, &shr, 0, CRED(),
1254 			    NULL);
1255 			shrlock_done = 0;
1256 		}
1257 
1258 		/*
1259 		 * The following clause was added to handle a problem
1260 		 * with NFS consistency.  It is possible that a lookup
1261 		 * of the file to be opened succeeded, but the file
1262 		 * itself doesn't actually exist on the server.  This
1263 		 * is chiefly due to the DNLC containing an entry for
1264 		 * the file which has been removed on the server.  In
1265 		 * this case, we just start over.  If there was some
1266 		 * other cause for the ESTALE error, then the lookup
1267 		 * of the file will fail and the error will be returned
1268 		 * above instead of looping around from here.
1269 		 */
1270 		VN_RELE(vp);
1271 		if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
1272 			goto top;
1273 	} else
1274 		*vpp = vp;
1275 	return (error);
1276 }
1277 
1278 /*
1279  * The following two accessor functions are for the NFSv4 server.  Since there
1280  * is no VOP_OPEN_UP/DOWNGRADE we need a way for the NFS server to keep the
1281  * vnode open counts correct when a client "upgrades" an open or does an
1282  * open_downgrade.  In NFS, an upgrade or downgrade can not only change the
1283  * open mode (add or subtract read or write), but also change the share/deny
1284  * modes.  However, share reservations are not integrated with OPEN, yet, so
1285  * we need to handle each separately.  These functions are cleaner than having
1286  * the NFS server manipulate the counts directly, however, nobody else should
1287  * use these functions.
1288  */
1289 void
1290 vn_open_upgrade(
1291 	vnode_t *vp,
1292 	int filemode)
1293 {
1294 	ASSERT(vp->v_type == VREG);
1295 
1296 	if (filemode & FREAD)
1297 		atomic_inc_32(&vp->v_rdcnt);
1298 	if (filemode & FWRITE)
1299 		atomic_inc_32(&vp->v_wrcnt);
1300 
1301 }
1302 
1303 void
1304 vn_open_downgrade(
1305 	vnode_t *vp,
1306 	int filemode)
1307 {
1308 	ASSERT(vp->v_type == VREG);
1309 
1310 	if (filemode & FREAD) {
1311 		ASSERT(vp->v_rdcnt > 0);
1312 		atomic_dec_32(&vp->v_rdcnt);
1313 	}
1314 	if (filemode & FWRITE) {
1315 		ASSERT(vp->v_wrcnt > 0);
1316 		atomic_dec_32(&vp->v_wrcnt);
1317 	}
1318 
1319 }
1320 
1321 int
1322 vn_create(
1323 	char *pnamep,
1324 	enum uio_seg seg,
1325 	struct vattr *vap,
1326 	enum vcexcl excl,
1327 	int mode,
1328 	struct vnode **vpp,
1329 	enum create why,
1330 	int flag,
1331 	mode_t umask)
1332 {
1333 	return (vn_createat(pnamep, seg, vap, excl, mode, vpp, why, flag,
1334 	    umask, NULL));
1335 }
1336 
1337 /*
1338  * Create a vnode (makenode).
1339  */
1340 int
1341 vn_createat(
1342 	char *pnamep,
1343 	enum uio_seg seg,
1344 	struct vattr *vap,
1345 	enum vcexcl excl,
1346 	int mode,
1347 	struct vnode **vpp,
1348 	enum create why,
1349 	int flag,
1350 	mode_t umask,
1351 	struct vnode *startvp)
1352 {
1353 	struct vnode *dvp;	/* ptr to parent dir vnode */
1354 	struct vnode *vp = NULL;
1355 	struct pathname pn;
1356 	int error;
1357 	int in_crit = 0;
1358 	struct vattr vattr;
1359 	enum symfollow follow;
1360 	int estale_retry = 0;
1361 	uint32_t auditing = AU_AUDITING();
1362 
1363 	ASSERT((vap->va_mask & (AT_TYPE|AT_MODE)) == (AT_TYPE|AT_MODE));
1364 
1365 	/* symlink interpretation */
1366 	if ((flag & FNOFOLLOW) || excl == EXCL)
1367 		follow = NO_FOLLOW;
1368 	else
1369 		follow = FOLLOW;
1370 	flag &= ~(FNOFOLLOW|FNOLINKS);
1371 
1372 top:
1373 	/*
1374 	 * Lookup directory.
1375 	 * If new object is a file, call lower level to create it.
1376 	 * Note that it is up to the lower level to enforce exclusive
1377 	 * creation, if the file is already there.
1378 	 * This allows the lower level to do whatever
1379 	 * locking or protocol that is needed to prevent races.
1380 	 * If the new object is directory call lower level to make
1381 	 * the new directory, with "." and "..".
1382 	 */
1383 	if (error = pn_get(pnamep, seg, &pn))
1384 		return (error);
1385 	if (auditing)
1386 		audit_vncreate_start();
1387 	dvp = NULL;
1388 	*vpp = NULL;
1389 	/*
1390 	 * lookup will find the parent directory for the vnode.
1391 	 * When it is done the pn holds the name of the entry
1392 	 * in the directory.
1393 	 * If this is a non-exclusive create we also find the node itself.
1394 	 */
1395 	error = lookuppnat(&pn, NULL, follow, &dvp,
1396 	    (excl == EXCL) ? NULLVPP : vpp, startvp);
1397 	if (error) {
1398 		pn_free(&pn);
1399 		if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
1400 			goto top;
1401 		if (why == CRMKDIR && error == EINVAL)
1402 			error = EEXIST;		/* SVID */
1403 		return (error);
1404 	}
1405 
1406 	if (why != CRMKNOD)
1407 		vap->va_mode &= ~VSVTX;
1408 
1409 	/*
1410 	 * If default ACLs are defined for the directory don't apply the
1411 	 * umask if umask is passed.
1412 	 */
1413 
1414 	if (umask) {
1415 
1416 		vsecattr_t vsec;
1417 
1418 		vsec.vsa_aclcnt = 0;
1419 		vsec.vsa_aclentp = NULL;
1420 		vsec.vsa_dfaclcnt = 0;
1421 		vsec.vsa_dfaclentp = NULL;
1422 		vsec.vsa_mask = VSA_DFACLCNT;
1423 		error = VOP_GETSECATTR(dvp, &vsec, 0, CRED(), NULL);
1424 		/*
1425 		 * If error is ENOSYS then treat it as no error
1426 		 * Don't want to force all file systems to support
1427 		 * aclent_t style of ACL's.
1428 		 */
1429 		if (error == ENOSYS)
1430 			error = 0;
1431 		if (error) {
1432 			if (*vpp != NULL)
1433 				VN_RELE(*vpp);
1434 			goto out;
1435 		} else {
1436 			/*
1437 			 * Apply the umask if no default ACLs.
1438 			 */
1439 			if (vsec.vsa_dfaclcnt == 0)
1440 				vap->va_mode &= ~umask;
1441 
1442 			/*
1443 			 * VOP_GETSECATTR() may have allocated memory for
1444 			 * ACLs we didn't request, so double-check and
1445 			 * free it if necessary.
1446 			 */
1447 			if (vsec.vsa_aclcnt && vsec.vsa_aclentp != NULL)
1448 				kmem_free((caddr_t)vsec.vsa_aclentp,
1449 				    vsec.vsa_aclcnt * sizeof (aclent_t));
1450 			if (vsec.vsa_dfaclcnt && vsec.vsa_dfaclentp != NULL)
1451 				kmem_free((caddr_t)vsec.vsa_dfaclentp,
1452 				    vsec.vsa_dfaclcnt * sizeof (aclent_t));
1453 		}
1454 	}
1455 
1456 	/*
1457 	 * In general we want to generate EROFS if the file system is
1458 	 * readonly.  However, POSIX (IEEE Std. 1003.1) section 5.3.1
1459 	 * documents the open system call, and it says that O_CREAT has no
1460 	 * effect if the file already exists.  Bug 1119649 states
1461 	 * that open(path, O_CREAT, ...) fails when attempting to open an
1462 	 * existing file on a read only file system.  Thus, the first part
1463 	 * of the following if statement has 3 checks:
1464 	 *	if the file exists &&
1465 	 *		it is being open with write access &&
1466 	 *		the file system is read only
1467 	 *	then generate EROFS
1468 	 */
1469 	if ((*vpp != NULL && (mode & VWRITE) && ISROFILE(*vpp)) ||
1470 	    (*vpp == NULL && dvp->v_vfsp->vfs_flag & VFS_RDONLY)) {
1471 		if (*vpp)
1472 			VN_RELE(*vpp);
1473 		error = EROFS;
1474 	} else if (excl == NONEXCL && *vpp != NULL) {
1475 		vnode_t *rvp;
1476 
1477 		/*
1478 		 * File already exists.  If a mandatory lock has been
1479 		 * applied, return error.
1480 		 */
1481 		vp = *vpp;
1482 		if (VOP_REALVP(vp, &rvp, NULL) != 0)
1483 			rvp = vp;
1484 		if ((vap->va_mask & AT_SIZE) && nbl_need_check(vp)) {
1485 			nbl_start_crit(vp, RW_READER);
1486 			in_crit = 1;
1487 		}
1488 		if (rvp->v_filocks != NULL || rvp->v_shrlocks != NULL) {
1489 			vattr.va_mask = AT_MODE|AT_SIZE;
1490 			if (error = VOP_GETATTR(vp, &vattr, 0, CRED(), NULL)) {
1491 				goto out;
1492 			}
1493 			if (MANDLOCK(vp, vattr.va_mode)) {
1494 				error = EAGAIN;
1495 				goto out;
1496 			}
1497 			/*
1498 			 * File cannot be truncated if non-blocking mandatory
1499 			 * locks are currently on the file.
1500 			 */
1501 			if ((vap->va_mask & AT_SIZE) && in_crit) {
1502 				u_offset_t offset;
1503 				ssize_t length;
1504 
1505 				offset = vap->va_size > vattr.va_size ?
1506 				    vattr.va_size : vap->va_size;
1507 				length = vap->va_size > vattr.va_size ?
1508 				    vap->va_size - vattr.va_size :
1509 				    vattr.va_size - vap->va_size;
1510 				if (nbl_conflict(vp, NBL_WRITE, offset,
1511 				    length, 0, NULL)) {
1512 					error = EACCES;
1513 					goto out;
1514 				}
1515 			}
1516 		}
1517 
1518 		/*
1519 		 * If the file is the root of a VFS, we've crossed a
1520 		 * mount point and the "containing" directory that we
1521 		 * acquired above (dvp) is irrelevant because it's in
1522 		 * a different file system.  We apply VOP_CREATE to the
1523 		 * target itself instead of to the containing directory
1524 		 * and supply a null path name to indicate (conventionally)
1525 		 * the node itself as the "component" of interest.
1526 		 *
1527 		 * The call to VOP_CREATE() is necessary to ensure
1528 		 * that the appropriate permission checks are made,
1529 		 * i.e. EISDIR, EACCES, etc.  We already know that vpp
1530 		 * exists since we are in the else condition where this
1531 		 * was checked.
1532 		 */
1533 		if (vp->v_flag & VROOT) {
1534 			ASSERT(why != CRMKDIR);
1535 			error = VOP_CREATE(vp, "", vap, excl, mode, vpp,
1536 			    CRED(), flag, NULL, NULL);
1537 			/*
1538 			 * If the create succeeded, it will have created a
1539 			 * new reference on a new vnode (*vpp) in the child
1540 			 * file system, so we want to drop our reference on
1541 			 * the old (vp) upon exit.
1542 			 */
1543 			goto out;
1544 		}
1545 
1546 		/*
1547 		 * Large File API - non-large open (FOFFMAX flag not set)
1548 		 * of regular file fails if the file size exceeds MAXOFF32_T.
1549 		 */
1550 		if (why != CRMKDIR &&
1551 		    !(flag & FOFFMAX) &&
1552 		    (vp->v_type == VREG)) {
1553 			vattr.va_mask = AT_SIZE;
1554 			if ((error = VOP_GETATTR(vp, &vattr, 0,
1555 			    CRED(), NULL))) {
1556 				goto out;
1557 			}
1558 			if ((vattr.va_size > (u_offset_t)MAXOFF32_T)) {
1559 				error = EOVERFLOW;
1560 				goto out;
1561 			}
1562 		}
1563 	}
1564 
1565 	if (error == 0) {
1566 		/*
1567 		 * Call mkdir() if specified, otherwise create().
1568 		 */
1569 		int must_be_dir = pn_fixslash(&pn);	/* trailing '/'? */
1570 
1571 		if (why == CRMKDIR)
1572 			/*
1573 			 * N.B., if vn_createat() ever requests
1574 			 * case-insensitive behavior then it will need
1575 			 * to be passed to VOP_MKDIR().  VOP_CREATE()
1576 			 * will already get it via "flag"
1577 			 */
1578 			error = VOP_MKDIR(dvp, pn.pn_path, vap, vpp, CRED(),
1579 			    NULL, 0, NULL);
1580 		else if (!must_be_dir)
1581 			error = VOP_CREATE(dvp, pn.pn_path, vap,
1582 			    excl, mode, vpp, CRED(), flag, NULL, NULL);
1583 		else
1584 			error = ENOTDIR;
1585 	}
1586 
1587 out:
1588 
1589 	if (auditing)
1590 		audit_vncreate_finish(*vpp, error);
1591 	if (in_crit) {
1592 		nbl_end_crit(vp);
1593 		in_crit = 0;
1594 	}
1595 	if (vp != NULL) {
1596 		VN_RELE(vp);
1597 		vp = NULL;
1598 	}
1599 	pn_free(&pn);
1600 	VN_RELE(dvp);
1601 	/*
1602 	 * The following clause was added to handle a problem
1603 	 * with NFS consistency.  It is possible that a lookup
1604 	 * of the file to be created succeeded, but the file
1605 	 * itself doesn't actually exist on the server.  This
1606 	 * is chiefly due to the DNLC containing an entry for
1607 	 * the file which has been removed on the server.  In
1608 	 * this case, we just start over.  If there was some
1609 	 * other cause for the ESTALE error, then the lookup
1610 	 * of the file will fail and the error will be returned
1611 	 * above instead of looping around from here.
1612 	 */
1613 	if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
1614 		goto top;
1615 	return (error);
1616 }
1617 
1618 int
1619 vn_link(char *from, char *to, enum uio_seg seg)
1620 {
1621 	return (vn_linkat(NULL, from, NO_FOLLOW, NULL, to, seg));
1622 }
1623 
1624 int
1625 vn_linkat(vnode_t *fstartvp, char *from, enum symfollow follow,
1626     vnode_t *tstartvp, char *to, enum uio_seg seg)
1627 {
1628 	struct vnode *fvp;		/* from vnode ptr */
1629 	struct vnode *tdvp;		/* to directory vnode ptr */
1630 	struct pathname pn;
1631 	int error;
1632 	struct vattr vattr;
1633 	dev_t fsid;
1634 	int estale_retry = 0;
1635 	uint32_t auditing = AU_AUDITING();
1636 
1637 top:
1638 	fvp = tdvp = NULL;
1639 	if (error = pn_get(to, seg, &pn))
1640 		return (error);
1641 	if (auditing && fstartvp != NULL)
1642 		audit_setfsat_path(1);
1643 	if (error = lookupnameat(from, seg, follow, NULLVPP, &fvp, fstartvp))
1644 		goto out;
1645 	if (auditing && tstartvp != NULL)
1646 		audit_setfsat_path(3);
1647 	if (error = lookuppnat(&pn, NULL, NO_FOLLOW, &tdvp, NULLVPP, tstartvp))
1648 		goto out;
1649 	/*
1650 	 * Make sure both source vnode and target directory vnode are
1651 	 * in the same vfs and that it is writeable.
1652 	 */
1653 	vattr.va_mask = AT_FSID;
1654 	if (error = VOP_GETATTR(fvp, &vattr, 0, CRED(), NULL))
1655 		goto out;
1656 	fsid = vattr.va_fsid;
1657 	vattr.va_mask = AT_FSID;
1658 	if (error = VOP_GETATTR(tdvp, &vattr, 0, CRED(), NULL))
1659 		goto out;
1660 	if (fsid != vattr.va_fsid) {
1661 		error = EXDEV;
1662 		goto out;
1663 	}
1664 	if (tdvp->v_vfsp->vfs_flag & VFS_RDONLY) {
1665 		error = EROFS;
1666 		goto out;
1667 	}
1668 	/*
1669 	 * Do the link.
1670 	 */
1671 	(void) pn_fixslash(&pn);
1672 	error = VOP_LINK(tdvp, fvp, pn.pn_path, CRED(), NULL, 0);
1673 out:
1674 	pn_free(&pn);
1675 	if (fvp)
1676 		VN_RELE(fvp);
1677 	if (tdvp)
1678 		VN_RELE(tdvp);
1679 	if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
1680 		goto top;
1681 	return (error);
1682 }
1683 
1684 int
1685 vn_rename(char *from, char *to, enum uio_seg seg)
1686 {
1687 	return (vn_renameat(NULL, from, NULL, to, seg));
1688 }
1689 
1690 int
1691 vn_renameat(vnode_t *fdvp, char *fname, vnode_t *tdvp,
1692     char *tname, enum uio_seg seg)
1693 {
1694 	int error;
1695 	struct vattr vattr;
1696 	struct pathname fpn;		/* from pathname */
1697 	struct pathname tpn;		/* to pathname */
1698 	dev_t fsid;
1699 	int in_crit_src, in_crit_targ;
1700 	vnode_t *fromvp, *fvp;
1701 	vnode_t *tovp, *targvp;
1702 	int estale_retry = 0;
1703 	uint32_t auditing = AU_AUDITING();
1704 
1705 top:
1706 	fvp = fromvp = tovp = targvp = NULL;
1707 	in_crit_src = in_crit_targ = 0;
1708 	/*
1709 	 * Get to and from pathnames.
1710 	 */
1711 	if (error = pn_get(fname, seg, &fpn))
1712 		return (error);
1713 	if (error = pn_get(tname, seg, &tpn)) {
1714 		pn_free(&fpn);
1715 		return (error);
1716 	}
1717 
1718 	/*
1719 	 * First we need to resolve the correct directories
1720 	 * The passed in directories may only be a starting point,
1721 	 * but we need the real directories the file(s) live in.
1722 	 * For example the fname may be something like usr/lib/sparc
1723 	 * and we were passed in the / directory, but we need to
1724 	 * use the lib directory for the rename.
1725 	 */
1726 
1727 	if (auditing && fdvp != NULL)
1728 		audit_setfsat_path(1);
1729 	/*
1730 	 * Lookup to and from directories.
1731 	 */
1732 	if (error = lookuppnat(&fpn, NULL, NO_FOLLOW, &fromvp, &fvp, fdvp)) {
1733 		goto out;
1734 	}
1735 
1736 	/*
1737 	 * Make sure there is an entry.
1738 	 */
1739 	if (fvp == NULL) {
1740 		error = ENOENT;
1741 		goto out;
1742 	}
1743 
1744 	if (auditing && tdvp != NULL)
1745 		audit_setfsat_path(3);
1746 	if (error = lookuppnat(&tpn, NULL, NO_FOLLOW, &tovp, &targvp, tdvp)) {
1747 		goto out;
1748 	}
1749 
1750 	/*
1751 	 * Make sure both the from vnode directory and the to directory
1752 	 * are in the same vfs and the to directory is writable.
1753 	 * We check fsid's, not vfs pointers, so loopback fs works.
1754 	 */
1755 	if (fromvp != tovp) {
1756 		vattr.va_mask = AT_FSID;
1757 		if (error = VOP_GETATTR(fromvp, &vattr, 0, CRED(), NULL))
1758 			goto out;
1759 		fsid = vattr.va_fsid;
1760 		vattr.va_mask = AT_FSID;
1761 		if (error = VOP_GETATTR(tovp, &vattr, 0, CRED(), NULL))
1762 			goto out;
1763 		if (fsid != vattr.va_fsid) {
1764 			error = EXDEV;
1765 			goto out;
1766 		}
1767 	}
1768 
1769 	if (tovp->v_vfsp->vfs_flag & VFS_RDONLY) {
1770 		error = EROFS;
1771 		goto out;
1772 	}
1773 
1774 	/*
1775 	 * Make sure "from" vp is not a mount point.
1776 	 * Note, lookup did traverse() already, so
1777 	 * we'll be looking at the mounted FS root.
1778 	 * (but allow files like mnttab)
1779 	 */
1780 	if ((fvp->v_flag & VROOT) != 0 && fvp->v_type == VDIR) {
1781 		error = EBUSY;
1782 		goto out;
1783 	}
1784 
1785 	if (targvp && (fvp != targvp)) {
1786 		nbl_start_crit(targvp, RW_READER);
1787 		in_crit_targ = 1;
1788 		if (nbl_conflict(targvp, NBL_REMOVE, 0, 0, 0, NULL)) {
1789 			error = EACCES;
1790 			goto out;
1791 		}
1792 	}
1793 
1794 	if (nbl_need_check(fvp)) {
1795 		nbl_start_crit(fvp, RW_READER);
1796 		in_crit_src = 1;
1797 		if (nbl_conflict(fvp, NBL_RENAME, 0, 0, 0, NULL)) {
1798 			error = EACCES;
1799 			goto out;
1800 		}
1801 	}
1802 
1803 	/*
1804 	 * Do the rename.
1805 	 */
1806 	(void) pn_fixslash(&tpn);
1807 	error = VOP_RENAME(fromvp, fpn.pn_path, tovp, tpn.pn_path, CRED(),
1808 	    NULL, 0);
1809 
1810 out:
1811 	pn_free(&fpn);
1812 	pn_free(&tpn);
1813 	if (in_crit_src)
1814 		nbl_end_crit(fvp);
1815 	if (in_crit_targ)
1816 		nbl_end_crit(targvp);
1817 	if (fromvp)
1818 		VN_RELE(fromvp);
1819 	if (tovp)
1820 		VN_RELE(tovp);
1821 	if (targvp)
1822 		VN_RELE(targvp);
1823 	if (fvp)
1824 		VN_RELE(fvp);
1825 	if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
1826 		goto top;
1827 	return (error);
1828 }
1829 
1830 /*
1831  * Remove a file or directory.
1832  */
1833 int
1834 vn_remove(char *fnamep, enum uio_seg seg, enum rm dirflag)
1835 {
1836 	return (vn_removeat(NULL, fnamep, seg, dirflag));
1837 }
1838 
1839 int
1840 vn_removeat(vnode_t *startvp, char *fnamep, enum uio_seg seg, enum rm dirflag)
1841 {
1842 	struct vnode *vp;		/* entry vnode */
1843 	struct vnode *dvp;		/* ptr to parent dir vnode */
1844 	struct vnode *coveredvp;
1845 	struct pathname pn;		/* name of entry */
1846 	enum vtype vtype;
1847 	int error;
1848 	struct vfs *vfsp;
1849 	struct vfs *dvfsp;	/* ptr to parent dir vfs */
1850 	int in_crit = 0;
1851 	int estale_retry = 0;
1852 
1853 top:
1854 	if (error = pn_get(fnamep, seg, &pn))
1855 		return (error);
1856 	dvp = vp = NULL;
1857 	if (error = lookuppnat(&pn, NULL, NO_FOLLOW, &dvp, &vp, startvp)) {
1858 		pn_free(&pn);
1859 		if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
1860 			goto top;
1861 		return (error);
1862 	}
1863 
1864 	/*
1865 	 * Make sure there is an entry.
1866 	 */
1867 	if (vp == NULL) {
1868 		error = ENOENT;
1869 		goto out;
1870 	}
1871 
1872 	vfsp = vp->v_vfsp;
1873 	dvfsp = dvp->v_vfsp;
1874 
1875 	/*
1876 	 * If the named file is the root of a mounted filesystem, fail,
1877 	 * unless it's marked unlinkable.  In that case, unmount the
1878 	 * filesystem and proceed to unlink the covered vnode.  (If the
1879 	 * covered vnode is a directory, use rmdir instead of unlink,
1880 	 * to avoid file system corruption.)
1881 	 */
1882 	if (vp->v_flag & VROOT) {
1883 		if ((vfsp->vfs_flag & VFS_UNLINKABLE) == 0) {
1884 			error = EBUSY;
1885 			goto out;
1886 		}
1887 
1888 		/*
1889 		 * Namefs specific code starts here.
1890 		 */
1891 
1892 		if (dirflag == RMDIRECTORY) {
1893 			/*
1894 			 * User called rmdir(2) on a file that has
1895 			 * been namefs mounted on top of.  Since
1896 			 * namefs doesn't allow directories to
1897 			 * be mounted on other files we know
1898 			 * vp is not of type VDIR so fail to operation.
1899 			 */
1900 			error = ENOTDIR;
1901 			goto out;
1902 		}
1903 
1904 		/*
1905 		 * If VROOT is still set after grabbing vp->v_lock,
1906 		 * noone has finished nm_unmount so far and coveredvp
1907 		 * is valid.
1908 		 * If we manage to grab vn_vfswlock(coveredvp) before releasing
1909 		 * vp->v_lock, any race window is eliminated.
1910 		 */
1911 
1912 		mutex_enter(&vp->v_lock);
1913 		if ((vp->v_flag & VROOT) == 0) {
1914 			/* Someone beat us to the unmount */
1915 			mutex_exit(&vp->v_lock);
1916 			error = EBUSY;
1917 			goto out;
1918 		}
1919 		vfsp = vp->v_vfsp;
1920 		coveredvp = vfsp->vfs_vnodecovered;
1921 		ASSERT(coveredvp);
1922 		/*
1923 		 * Note: Implementation of vn_vfswlock shows that ordering of
1924 		 * v_lock / vn_vfswlock is not an issue here.
1925 		 */
1926 		error = vn_vfswlock(coveredvp);
1927 		mutex_exit(&vp->v_lock);
1928 
1929 		if (error)
1930 			goto out;
1931 
1932 		VN_HOLD(coveredvp);
1933 		VN_RELE(vp);
1934 		error = dounmount(vfsp, 0, CRED());
1935 
1936 		/*
1937 		 * Unmounted the namefs file system; now get
1938 		 * the object it was mounted over.
1939 		 */
1940 		vp = coveredvp;
1941 		/*
1942 		 * If namefs was mounted over a directory, then
1943 		 * we want to use rmdir() instead of unlink().
1944 		 */
1945 		if (vp->v_type == VDIR)
1946 			dirflag = RMDIRECTORY;
1947 
1948 		if (error)
1949 			goto out;
1950 	}
1951 
1952 	/*
1953 	 * Make sure filesystem is writeable.
1954 	 * We check the parent directory's vfs in case this is an lofs vnode.
1955 	 */
1956 	if (dvfsp && dvfsp->vfs_flag & VFS_RDONLY) {
1957 		error = EROFS;
1958 		goto out;
1959 	}
1960 
1961 	vtype = vp->v_type;
1962 
1963 	/*
1964 	 * If there is the possibility of an nbmand share reservation, make
1965 	 * sure it's okay to remove the file.  Keep a reference to the
1966 	 * vnode, so that we can exit the nbl critical region after
1967 	 * calling VOP_REMOVE.
1968 	 * If there is no possibility of an nbmand share reservation,
1969 	 * release the vnode reference now.  Filesystems like NFS may
1970 	 * behave differently if there is an extra reference, so get rid of
1971 	 * this one.  Fortunately, we can't have nbmand mounts on NFS
1972 	 * filesystems.
1973 	 */
1974 	if (nbl_need_check(vp)) {
1975 		nbl_start_crit(vp, RW_READER);
1976 		in_crit = 1;
1977 		if (nbl_conflict(vp, NBL_REMOVE, 0, 0, 0, NULL)) {
1978 			error = EACCES;
1979 			goto out;
1980 		}
1981 	} else {
1982 		VN_RELE(vp);
1983 		vp = NULL;
1984 	}
1985 
1986 	if (dirflag == RMDIRECTORY) {
1987 		/*
1988 		 * Caller is using rmdir(2), which can only be applied to
1989 		 * directories.
1990 		 */
1991 		if (vtype != VDIR) {
1992 			error = ENOTDIR;
1993 		} else {
1994 			vnode_t *cwd;
1995 			proc_t *pp = curproc;
1996 
1997 			mutex_enter(&pp->p_lock);
1998 			cwd = PTOU(pp)->u_cdir;
1999 			VN_HOLD(cwd);
2000 			mutex_exit(&pp->p_lock);
2001 			error = VOP_RMDIR(dvp, pn.pn_path, cwd, CRED(),
2002 			    NULL, 0);
2003 			VN_RELE(cwd);
2004 		}
2005 	} else {
2006 		/*
2007 		 * Unlink(2) can be applied to anything.
2008 		 */
2009 		error = VOP_REMOVE(dvp, pn.pn_path, CRED(), NULL, 0);
2010 	}
2011 
2012 out:
2013 	pn_free(&pn);
2014 	if (in_crit) {
2015 		nbl_end_crit(vp);
2016 		in_crit = 0;
2017 	}
2018 	if (vp != NULL)
2019 		VN_RELE(vp);
2020 	if (dvp != NULL)
2021 		VN_RELE(dvp);
2022 	if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
2023 		goto top;
2024 	return (error);
2025 }
2026 
2027 /*
2028  * Utility function to compare equality of vnodes.
2029  * Compare the underlying real vnodes, if there are underlying vnodes.
2030  * This is a more thorough comparison than the VN_CMP() macro provides.
2031  */
2032 int
2033 vn_compare(vnode_t *vp1, vnode_t *vp2)
2034 {
2035 	vnode_t *realvp;
2036 
2037 	if (vp1 != NULL && VOP_REALVP(vp1, &realvp, NULL) == 0)
2038 		vp1 = realvp;
2039 	if (vp2 != NULL && VOP_REALVP(vp2, &realvp, NULL) == 0)
2040 		vp2 = realvp;
2041 	return (VN_CMP(vp1, vp2));
2042 }
2043 
2044 /*
2045  * The number of locks to hash into.  This value must be a power
2046  * of 2 minus 1 and should probably also be prime.
2047  */
2048 #define	NUM_BUCKETS	1023
2049 
2050 struct  vn_vfslocks_bucket {
2051 	kmutex_t vb_lock;
2052 	vn_vfslocks_entry_t *vb_list;
2053 	char pad[64 - sizeof (kmutex_t) - sizeof (void *)];
2054 };
2055 
2056 /*
2057  * Total number of buckets will be NUM_BUCKETS + 1 .
2058  */
2059 
2060 #pragma	align	64(vn_vfslocks_buckets)
2061 static	struct vn_vfslocks_bucket	vn_vfslocks_buckets[NUM_BUCKETS + 1];
2062 
2063 #define	VN_VFSLOCKS_SHIFT	9
2064 
2065 #define	VN_VFSLOCKS_HASH(vfsvpptr)	\
2066 	((((intptr_t)(vfsvpptr)) >> VN_VFSLOCKS_SHIFT) & NUM_BUCKETS)
2067 
2068 /*
2069  * vn_vfslocks_getlock() uses an HASH scheme to generate
2070  * rwstlock using vfs/vnode pointer passed to it.
2071  *
2072  * vn_vfslocks_rele() releases a reference in the
2073  * HASH table which allows the entry allocated by
2074  * vn_vfslocks_getlock() to be freed at a later
2075  * stage when the refcount drops to zero.
2076  */
2077 
2078 vn_vfslocks_entry_t *
2079 vn_vfslocks_getlock(void *vfsvpptr)
2080 {
2081 	struct vn_vfslocks_bucket *bp;
2082 	vn_vfslocks_entry_t *vep;
2083 	vn_vfslocks_entry_t *tvep;
2084 
2085 	ASSERT(vfsvpptr != NULL);
2086 	bp = &vn_vfslocks_buckets[VN_VFSLOCKS_HASH(vfsvpptr)];
2087 
2088 	mutex_enter(&bp->vb_lock);
2089 	for (vep = bp->vb_list; vep != NULL; vep = vep->ve_next) {
2090 		if (vep->ve_vpvfs == vfsvpptr) {
2091 			vep->ve_refcnt++;
2092 			mutex_exit(&bp->vb_lock);
2093 			return (vep);
2094 		}
2095 	}
2096 	mutex_exit(&bp->vb_lock);
2097 	vep = kmem_alloc(sizeof (*vep), KM_SLEEP);
2098 	rwst_init(&vep->ve_lock, NULL, RW_DEFAULT, NULL);
2099 	vep->ve_vpvfs = (char *)vfsvpptr;
2100 	vep->ve_refcnt = 1;
2101 	mutex_enter(&bp->vb_lock);
2102 	for (tvep = bp->vb_list; tvep != NULL; tvep = tvep->ve_next) {
2103 		if (tvep->ve_vpvfs == vfsvpptr) {
2104 			tvep->ve_refcnt++;
2105 			mutex_exit(&bp->vb_lock);
2106 
2107 			/*
2108 			 * There is already an entry in the hash
2109 			 * destroy what we just allocated.
2110 			 */
2111 			rwst_destroy(&vep->ve_lock);
2112 			kmem_free(vep, sizeof (*vep));
2113 			return (tvep);
2114 		}
2115 	}
2116 	vep->ve_next = bp->vb_list;
2117 	bp->vb_list = vep;
2118 	mutex_exit(&bp->vb_lock);
2119 	return (vep);
2120 }
2121 
2122 void
2123 vn_vfslocks_rele(vn_vfslocks_entry_t *vepent)
2124 {
2125 	struct vn_vfslocks_bucket *bp;
2126 	vn_vfslocks_entry_t *vep;
2127 	vn_vfslocks_entry_t *pvep;
2128 
2129 	ASSERT(vepent != NULL);
2130 	ASSERT(vepent->ve_vpvfs != NULL);
2131 
2132 	bp = &vn_vfslocks_buckets[VN_VFSLOCKS_HASH(vepent->ve_vpvfs)];
2133 
2134 	mutex_enter(&bp->vb_lock);
2135 	vepent->ve_refcnt--;
2136 
2137 	if ((int32_t)vepent->ve_refcnt < 0)
2138 		cmn_err(CE_PANIC, "vn_vfslocks_rele: refcount negative");
2139 
2140 	pvep = NULL;
2141 	if (vepent->ve_refcnt == 0) {
2142 		for (vep = bp->vb_list; vep != NULL; vep = vep->ve_next) {
2143 			if (vep->ve_vpvfs == vepent->ve_vpvfs) {
2144 				if (pvep == NULL)
2145 					bp->vb_list = vep->ve_next;
2146 				else {
2147 					pvep->ve_next = vep->ve_next;
2148 				}
2149 				mutex_exit(&bp->vb_lock);
2150 				rwst_destroy(&vep->ve_lock);
2151 				kmem_free(vep, sizeof (*vep));
2152 				return;
2153 			}
2154 			pvep = vep;
2155 		}
2156 		cmn_err(CE_PANIC, "vn_vfslocks_rele: vp/vfs not found");
2157 	}
2158 	mutex_exit(&bp->vb_lock);
2159 }
2160 
2161 /*
2162  * vn_vfswlock_wait is used to implement a lock which is logically a writers
2163  * lock protecting the v_vfsmountedhere field.
2164  * vn_vfswlock_wait has been modified to be similar to vn_vfswlock,
2165  * except that it blocks to acquire the lock VVFSLOCK.
2166  *
2167  * traverse() and routines re-implementing part of traverse (e.g. autofs)
2168  * need to hold this lock. mount(), vn_rename(), vn_remove() and so on
2169  * need the non-blocking version of the writers lock i.e. vn_vfswlock
2170  */
2171 int
2172 vn_vfswlock_wait(vnode_t *vp)
2173 {
2174 	int retval;
2175 	vn_vfslocks_entry_t *vpvfsentry;
2176 	ASSERT(vp != NULL);
2177 
2178 	vpvfsentry = vn_vfslocks_getlock(vp);
2179 	retval = rwst_enter_sig(&vpvfsentry->ve_lock, RW_WRITER);
2180 
2181 	if (retval == EINTR) {
2182 		vn_vfslocks_rele(vpvfsentry);
2183 		return (EINTR);
2184 	}
2185 	return (retval);
2186 }
2187 
2188 int
2189 vn_vfsrlock_wait(vnode_t *vp)
2190 {
2191 	int retval;
2192 	vn_vfslocks_entry_t *vpvfsentry;
2193 	ASSERT(vp != NULL);
2194 
2195 	vpvfsentry = vn_vfslocks_getlock(vp);
2196 	retval = rwst_enter_sig(&vpvfsentry->ve_lock, RW_READER);
2197 
2198 	if (retval == EINTR) {
2199 		vn_vfslocks_rele(vpvfsentry);
2200 		return (EINTR);
2201 	}
2202 
2203 	return (retval);
2204 }
2205 
2206 
2207 /*
2208  * vn_vfswlock is used to implement a lock which is logically a writers lock
2209  * protecting the v_vfsmountedhere field.
2210  */
2211 int
2212 vn_vfswlock(vnode_t *vp)
2213 {
2214 	vn_vfslocks_entry_t *vpvfsentry;
2215 
2216 	/*
2217 	 * If vp is NULL then somebody is trying to lock the covered vnode
2218 	 * of /.  (vfs_vnodecovered is NULL for /).  This situation will
2219 	 * only happen when unmounting /.  Since that operation will fail
2220 	 * anyway, return EBUSY here instead of in VFS_UNMOUNT.
2221 	 */
2222 	if (vp == NULL)
2223 		return (EBUSY);
2224 
2225 	vpvfsentry = vn_vfslocks_getlock(vp);
2226 
2227 	if (rwst_tryenter(&vpvfsentry->ve_lock, RW_WRITER))
2228 		return (0);
2229 
2230 	vn_vfslocks_rele(vpvfsentry);
2231 	return (EBUSY);
2232 }
2233 
2234 int
2235 vn_vfsrlock(vnode_t *vp)
2236 {
2237 	vn_vfslocks_entry_t *vpvfsentry;
2238 
2239 	/*
2240 	 * If vp is NULL then somebody is trying to lock the covered vnode
2241 	 * of /.  (vfs_vnodecovered is NULL for /).  This situation will
2242 	 * only happen when unmounting /.  Since that operation will fail
2243 	 * anyway, return EBUSY here instead of in VFS_UNMOUNT.
2244 	 */
2245 	if (vp == NULL)
2246 		return (EBUSY);
2247 
2248 	vpvfsentry = vn_vfslocks_getlock(vp);
2249 
2250 	if (rwst_tryenter(&vpvfsentry->ve_lock, RW_READER))
2251 		return (0);
2252 
2253 	vn_vfslocks_rele(vpvfsentry);
2254 	return (EBUSY);
2255 }
2256 
2257 void
2258 vn_vfsunlock(vnode_t *vp)
2259 {
2260 	vn_vfslocks_entry_t *vpvfsentry;
2261 
2262 	/*
2263 	 * ve_refcnt needs to be decremented twice.
2264 	 * 1. To release refernce after a call to vn_vfslocks_getlock()
2265 	 * 2. To release the reference from the locking routines like
2266 	 *    vn_vfsrlock/vn_vfswlock etc,.
2267 	 */
2268 	vpvfsentry = vn_vfslocks_getlock(vp);
2269 	vn_vfslocks_rele(vpvfsentry);
2270 
2271 	rwst_exit(&vpvfsentry->ve_lock);
2272 	vn_vfslocks_rele(vpvfsentry);
2273 }
2274 
2275 int
2276 vn_vfswlock_held(vnode_t *vp)
2277 {
2278 	int held;
2279 	vn_vfslocks_entry_t *vpvfsentry;
2280 
2281 	ASSERT(vp != NULL);
2282 
2283 	vpvfsentry = vn_vfslocks_getlock(vp);
2284 	held = rwst_lock_held(&vpvfsentry->ve_lock, RW_WRITER);
2285 
2286 	vn_vfslocks_rele(vpvfsentry);
2287 	return (held);
2288 }
2289 
2290 
2291 int
2292 vn_make_ops(
2293 	const char *name,			/* Name of file system */
2294 	const fs_operation_def_t *templ,	/* Operation specification */
2295 	vnodeops_t **actual)			/* Return the vnodeops */
2296 {
2297 	int unused_ops;
2298 	int error;
2299 
2300 	*actual = (vnodeops_t *)kmem_alloc(sizeof (vnodeops_t), KM_SLEEP);
2301 
2302 	(*actual)->vnop_name = name;
2303 
2304 	error = fs_build_vector(*actual, &unused_ops, vn_ops_table, templ);
2305 	if (error) {
2306 		kmem_free(*actual, sizeof (vnodeops_t));
2307 	}
2308 
2309 #if DEBUG
2310 	if (unused_ops != 0)
2311 		cmn_err(CE_WARN, "vn_make_ops: %s: %d operations supplied "
2312 		    "but not used", name, unused_ops);
2313 #endif
2314 
2315 	return (error);
2316 }
2317 
2318 /*
2319  * Free the vnodeops created as a result of vn_make_ops()
2320  */
2321 void
2322 vn_freevnodeops(vnodeops_t *vnops)
2323 {
2324 	kmem_free(vnops, sizeof (vnodeops_t));
2325 }
2326 
2327 /*
2328  * Vnode cache.
2329  */
2330 
2331 /* ARGSUSED */
2332 static int
2333 vn_cache_constructor(void *buf, void *cdrarg, int kmflags)
2334 {
2335 	struct vnode *vp;
2336 
2337 	vp = buf;
2338 
2339 	mutex_init(&vp->v_lock, NULL, MUTEX_DEFAULT, NULL);
2340 	mutex_init(&vp->v_vsd_lock, NULL, MUTEX_DEFAULT, NULL);
2341 	cv_init(&vp->v_cv, NULL, CV_DEFAULT, NULL);
2342 	rw_init(&vp->v_nbllock, NULL, RW_DEFAULT, NULL);
2343 	vp->v_femhead = NULL;	/* Must be done before vn_reinit() */
2344 	vp->v_path = vn_vpath_empty;
2345 	vp->v_path_stamp = 0;
2346 	vp->v_mpssdata = NULL;
2347 	vp->v_vsd = NULL;
2348 	vp->v_fopdata = NULL;
2349 
2350 	return (0);
2351 }
2352 
2353 /* ARGSUSED */
2354 static void
2355 vn_cache_destructor(void *buf, void *cdrarg)
2356 {
2357 	struct vnode *vp;
2358 
2359 	vp = buf;
2360 
2361 	rw_destroy(&vp->v_nbllock);
2362 	cv_destroy(&vp->v_cv);
2363 	mutex_destroy(&vp->v_vsd_lock);
2364 	mutex_destroy(&vp->v_lock);
2365 }
2366 
2367 void
2368 vn_create_cache(void)
2369 {
2370 	/* LINTED */
2371 	ASSERT((1 << VNODE_ALIGN_LOG2) ==
2372 	    P2ROUNDUP(sizeof (struct vnode), VNODE_ALIGN));
2373 	vn_cache = kmem_cache_create("vn_cache", sizeof (struct vnode),
2374 	    VNODE_ALIGN, vn_cache_constructor, vn_cache_destructor, NULL, NULL,
2375 	    NULL, 0);
2376 }
2377 
2378 void
2379 vn_destroy_cache(void)
2380 {
2381 	kmem_cache_destroy(vn_cache);
2382 }
2383 
2384 /*
2385  * Used by file systems when fs-specific nodes (e.g., ufs inodes) are
2386  * cached by the file system and vnodes remain associated.
2387  */
2388 void
2389 vn_recycle(vnode_t *vp)
2390 {
2391 	ASSERT(vp->v_pages == NULL);
2392 	VERIFY(vp->v_path != NULL);
2393 
2394 	/*
2395 	 * XXX - This really belongs in vn_reinit(), but we have some issues
2396 	 * with the counts.  Best to have it here for clean initialization.
2397 	 */
2398 	vp->v_rdcnt = 0;
2399 	vp->v_wrcnt = 0;
2400 	vp->v_mmap_read = 0;
2401 	vp->v_mmap_write = 0;
2402 
2403 	/*
2404 	 * If FEM was in use, make sure everything gets cleaned up
2405 	 * NOTE: vp->v_femhead is initialized to NULL in the vnode
2406 	 * constructor.
2407 	 */
2408 	if (vp->v_femhead) {
2409 		/* XXX - There should be a free_femhead() that does all this */
2410 		ASSERT(vp->v_femhead->femh_list == NULL);
2411 		mutex_destroy(&vp->v_femhead->femh_lock);
2412 		kmem_free(vp->v_femhead, sizeof (*(vp->v_femhead)));
2413 		vp->v_femhead = NULL;
2414 	}
2415 	if (vp->v_path != vn_vpath_empty) {
2416 		kmem_free(vp->v_path, strlen(vp->v_path) + 1);
2417 		vp->v_path = vn_vpath_empty;
2418 	}
2419 	vp->v_path_stamp = 0;
2420 
2421 	if (vp->v_fopdata != NULL) {
2422 		free_fopdata(vp);
2423 	}
2424 	vp->v_mpssdata = NULL;
2425 	vsd_free(vp);
2426 }
2427 
2428 /*
2429  * Used to reset the vnode fields including those that are directly accessible
2430  * as well as those which require an accessor function.
2431  *
2432  * Does not initialize:
2433  *	synchronization objects: v_lock, v_vsd_lock, v_nbllock, v_cv
2434  *	v_data (since FS-nodes and vnodes point to each other and should
2435  *		be updated simultaneously)
2436  *	v_op (in case someone needs to make a VOP call on this object)
2437  */
2438 void
2439 vn_reinit(vnode_t *vp)
2440 {
2441 	vp->v_count = 1;
2442 	vp->v_count_dnlc = 0;
2443 	vp->v_vfsp = NULL;
2444 	vp->v_stream = NULL;
2445 	vp->v_vfsmountedhere = NULL;
2446 	vp->v_flag = 0;
2447 	vp->v_type = VNON;
2448 	vp->v_rdev = NODEV;
2449 
2450 	vp->v_filocks = NULL;
2451 	vp->v_shrlocks = NULL;
2452 	vp->v_pages = NULL;
2453 
2454 	vp->v_locality = NULL;
2455 	vp->v_xattrdir = NULL;
2456 
2457 	/*
2458 	 * In a few specific instances, vn_reinit() is used to initialize
2459 	 * locally defined vnode_t instances.  Lacking the construction offered
2460 	 * by vn_alloc(), these vnodes require v_path initialization.
2461 	 */
2462 	if (vp->v_path == NULL) {
2463 		vp->v_path = vn_vpath_empty;
2464 	}
2465 
2466 	/* Handles v_femhead, v_path, and the r/w/map counts */
2467 	vn_recycle(vp);
2468 }
2469 
2470 vnode_t *
2471 vn_alloc(int kmflag)
2472 {
2473 	vnode_t *vp;
2474 
2475 	vp = kmem_cache_alloc(vn_cache, kmflag);
2476 
2477 	if (vp != NULL) {
2478 		vp->v_femhead = NULL;	/* Must be done before vn_reinit() */
2479 		vp->v_fopdata = NULL;
2480 		vn_reinit(vp);
2481 	}
2482 
2483 	return (vp);
2484 }
2485 
2486 void
2487 vn_free(vnode_t *vp)
2488 {
2489 	ASSERT(vp->v_shrlocks == NULL);
2490 	ASSERT(vp->v_filocks == NULL);
2491 
2492 	/*
2493 	 * Some file systems call vn_free() with v_count of zero,
2494 	 * some with v_count of 1.  In any case, the value should
2495 	 * never be anything else.
2496 	 */
2497 	ASSERT((vp->v_count == 0) || (vp->v_count == 1));
2498 	ASSERT(vp->v_count_dnlc == 0);
2499 	VERIFY(vp->v_path != NULL);
2500 	if (vp->v_path != vn_vpath_empty) {
2501 		kmem_free(vp->v_path, strlen(vp->v_path) + 1);
2502 		vp->v_path = vn_vpath_empty;
2503 	}
2504 
2505 	/* If FEM was in use, make sure everything gets cleaned up */
2506 	if (vp->v_femhead) {
2507 		/* XXX - There should be a free_femhead() that does all this */
2508 		ASSERT(vp->v_femhead->femh_list == NULL);
2509 		mutex_destroy(&vp->v_femhead->femh_lock);
2510 		kmem_free(vp->v_femhead, sizeof (*(vp->v_femhead)));
2511 		vp->v_femhead = NULL;
2512 	}
2513 
2514 	if (vp->v_fopdata != NULL) {
2515 		free_fopdata(vp);
2516 	}
2517 	vp->v_mpssdata = NULL;
2518 	vsd_free(vp);
2519 	kmem_cache_free(vn_cache, vp);
2520 }
2521 
2522 /*
2523  * vnode status changes, should define better states than 1, 0.
2524  */
2525 void
2526 vn_reclaim(vnode_t *vp)
2527 {
2528 	vfs_t   *vfsp = vp->v_vfsp;
2529 
2530 	if (vfsp == NULL ||
2531 	    vfsp->vfs_implp == NULL || vfsp->vfs_femhead == NULL) {
2532 		return;
2533 	}
2534 	(void) VFS_VNSTATE(vfsp, vp, VNTRANS_RECLAIMED);
2535 }
2536 
2537 void
2538 vn_idle(vnode_t *vp)
2539 {
2540 	vfs_t   *vfsp = vp->v_vfsp;
2541 
2542 	if (vfsp == NULL ||
2543 	    vfsp->vfs_implp == NULL || vfsp->vfs_femhead == NULL) {
2544 		return;
2545 	}
2546 	(void) VFS_VNSTATE(vfsp, vp, VNTRANS_IDLED);
2547 }
2548 void
2549 vn_exists(vnode_t *vp)
2550 {
2551 	vfs_t   *vfsp = vp->v_vfsp;
2552 
2553 	if (vfsp == NULL ||
2554 	    vfsp->vfs_implp == NULL || vfsp->vfs_femhead == NULL) {
2555 		return;
2556 	}
2557 	(void) VFS_VNSTATE(vfsp, vp, VNTRANS_EXISTS);
2558 }
2559 
2560 void
2561 vn_invalid(vnode_t *vp)
2562 {
2563 	vfs_t   *vfsp = vp->v_vfsp;
2564 
2565 	if (vfsp == NULL ||
2566 	    vfsp->vfs_implp == NULL || vfsp->vfs_femhead == NULL) {
2567 		return;
2568 	}
2569 	(void) VFS_VNSTATE(vfsp, vp, VNTRANS_DESTROYED);
2570 }
2571 
2572 /* Vnode event notification */
2573 
2574 int
2575 vnevent_support(vnode_t *vp, caller_context_t *ct)
2576 {
2577 	if (vp == NULL)
2578 		return (EINVAL);
2579 
2580 	return (VOP_VNEVENT(vp, VE_SUPPORT, NULL, NULL, ct));
2581 }
2582 
2583 void
2584 vnevent_rename_src(vnode_t *vp, vnode_t *dvp, char *name, caller_context_t *ct)
2585 {
2586 	if (vp == NULL || vp->v_femhead == NULL) {
2587 		return;
2588 	}
2589 	(void) VOP_VNEVENT(vp, VE_RENAME_SRC, dvp, name, ct);
2590 }
2591 
2592 void
2593 vnevent_rename_dest(vnode_t *vp, vnode_t *dvp, char *name,
2594     caller_context_t *ct)
2595 {
2596 	if (vp == NULL || vp->v_femhead == NULL) {
2597 		return;
2598 	}
2599 	(void) VOP_VNEVENT(vp, VE_RENAME_DEST, dvp, name, ct);
2600 }
2601 
2602 void
2603 vnevent_rename_dest_dir(vnode_t *vp, caller_context_t *ct)
2604 {
2605 	if (vp == NULL || vp->v_femhead == NULL) {
2606 		return;
2607 	}
2608 	(void) VOP_VNEVENT(vp, VE_RENAME_DEST_DIR, NULL, NULL, ct);
2609 }
2610 
2611 void
2612 vnevent_remove(vnode_t *vp, vnode_t *dvp, char *name, caller_context_t *ct)
2613 {
2614 	if (vp == NULL || vp->v_femhead == NULL) {
2615 		return;
2616 	}
2617 	(void) VOP_VNEVENT(vp, VE_REMOVE, dvp, name, ct);
2618 }
2619 
2620 void
2621 vnevent_rmdir(vnode_t *vp, vnode_t *dvp, char *name, caller_context_t *ct)
2622 {
2623 	if (vp == NULL || vp->v_femhead == NULL) {
2624 		return;
2625 	}
2626 	(void) VOP_VNEVENT(vp, VE_RMDIR, dvp, name, ct);
2627 }
2628 
2629 void
2630 vnevent_pre_rename_src(vnode_t *vp, vnode_t *dvp, char *name,
2631     caller_context_t *ct)
2632 {
2633 	if (vp == NULL || vp->v_femhead == NULL) {
2634 		return;
2635 	}
2636 	(void) VOP_VNEVENT(vp, VE_PRE_RENAME_SRC, dvp, name, ct);
2637 }
2638 
2639 void
2640 vnevent_pre_rename_dest(vnode_t *vp, vnode_t *dvp, char *name,
2641     caller_context_t *ct)
2642 {
2643 	if (vp == NULL || vp->v_femhead == NULL) {
2644 		return;
2645 	}
2646 	(void) VOP_VNEVENT(vp, VE_PRE_RENAME_DEST, dvp, name, ct);
2647 }
2648 
2649 void
2650 vnevent_pre_rename_dest_dir(vnode_t *vp, vnode_t *nvp, char *name,
2651     caller_context_t *ct)
2652 {
2653 	if (vp == NULL || vp->v_femhead == NULL) {
2654 		return;
2655 	}
2656 	(void) VOP_VNEVENT(vp, VE_PRE_RENAME_DEST_DIR, nvp, name, ct);
2657 }
2658 
2659 void
2660 vnevent_create(vnode_t *vp, caller_context_t *ct)
2661 {
2662 	if (vp == NULL || vp->v_femhead == NULL) {
2663 		return;
2664 	}
2665 	(void) VOP_VNEVENT(vp, VE_CREATE, NULL, NULL, ct);
2666 }
2667 
2668 void
2669 vnevent_link(vnode_t *vp, caller_context_t *ct)
2670 {
2671 	if (vp == NULL || vp->v_femhead == NULL) {
2672 		return;
2673 	}
2674 	(void) VOP_VNEVENT(vp, VE_LINK, NULL, NULL, ct);
2675 }
2676 
2677 void
2678 vnevent_mountedover(vnode_t *vp, caller_context_t *ct)
2679 {
2680 	if (vp == NULL || vp->v_femhead == NULL) {
2681 		return;
2682 	}
2683 	(void) VOP_VNEVENT(vp, VE_MOUNTEDOVER, NULL, NULL, ct);
2684 }
2685 
2686 void
2687 vnevent_truncate(vnode_t *vp, caller_context_t *ct)
2688 {
2689 	if (vp == NULL || vp->v_femhead == NULL) {
2690 		return;
2691 	}
2692 	(void) VOP_VNEVENT(vp, VE_TRUNCATE, NULL, NULL, ct);
2693 }
2694 
2695 /*
2696  * Vnode accessors.
2697  */
2698 
2699 int
2700 vn_is_readonly(vnode_t *vp)
2701 {
2702 	return (vp->v_vfsp->vfs_flag & VFS_RDONLY);
2703 }
2704 
2705 int
2706 vn_has_flocks(vnode_t *vp)
2707 {
2708 	return (vp->v_filocks != NULL);
2709 }
2710 
2711 int
2712 vn_has_mandatory_locks(vnode_t *vp, int mode)
2713 {
2714 	return ((vp->v_filocks != NULL) && (MANDLOCK(vp, mode)));
2715 }
2716 
2717 int
2718 vn_has_cached_data(vnode_t *vp)
2719 {
2720 	return (vp->v_pages != NULL);
2721 }
2722 
2723 /*
2724  * Return 0 if the vnode in question shouldn't be permitted into a zone via
2725  * zone_enter(2).
2726  */
2727 int
2728 vn_can_change_zones(vnode_t *vp)
2729 {
2730 	struct vfssw *vswp;
2731 	int allow = 1;
2732 	vnode_t *rvp;
2733 
2734 	if (nfs_global_client_only != 0)
2735 		return (1);
2736 
2737 	/*
2738 	 * We always want to look at the underlying vnode if there is one.
2739 	 */
2740 	if (VOP_REALVP(vp, &rvp, NULL) != 0)
2741 		rvp = vp;
2742 	/*
2743 	 * Some pseudo filesystems (including doorfs) don't actually register
2744 	 * their vfsops_t, so the following may return NULL; we happily let
2745 	 * such vnodes switch zones.
2746 	 */
2747 	vswp = vfs_getvfsswbyvfsops(vfs_getops(rvp->v_vfsp));
2748 	if (vswp != NULL) {
2749 		if (vswp->vsw_flag & VSW_NOTZONESAFE)
2750 			allow = 0;
2751 		vfs_unrefvfssw(vswp);
2752 	}
2753 	return (allow);
2754 }
2755 
2756 /*
2757  * Return nonzero if the vnode is a mount point, zero if not.
2758  */
2759 int
2760 vn_ismntpt(vnode_t *vp)
2761 {
2762 	return (vp->v_vfsmountedhere != NULL);
2763 }
2764 
2765 /* Retrieve the vfs (if any) mounted on this vnode */
2766 vfs_t *
2767 vn_mountedvfs(vnode_t *vp)
2768 {
2769 	return (vp->v_vfsmountedhere);
2770 }
2771 
2772 /*
2773  * Return nonzero if the vnode is referenced by the dnlc, zero if not.
2774  */
2775 int
2776 vn_in_dnlc(vnode_t *vp)
2777 {
2778 	return (vp->v_count_dnlc > 0);
2779 }
2780 
2781 /*
2782  * vn_has_other_opens() checks whether a particular file is opened by more than
2783  * just the caller and whether the open is for read and/or write.
2784  * This routine is for calling after the caller has already called VOP_OPEN()
2785  * and the caller wishes to know if they are the only one with it open for
2786  * the mode(s) specified.
2787  *
2788  * Vnode counts are only kept on regular files (v_type=VREG).
2789  */
2790 int
2791 vn_has_other_opens(
2792 	vnode_t *vp,
2793 	v_mode_t mode)
2794 {
2795 
2796 	ASSERT(vp != NULL);
2797 
2798 	switch (mode) {
2799 	case V_WRITE:
2800 		if (vp->v_wrcnt > 1)
2801 			return (V_TRUE);
2802 		break;
2803 	case V_RDORWR:
2804 		if ((vp->v_rdcnt > 1) || (vp->v_wrcnt > 1))
2805 			return (V_TRUE);
2806 		break;
2807 	case V_RDANDWR:
2808 		if ((vp->v_rdcnt > 1) && (vp->v_wrcnt > 1))
2809 			return (V_TRUE);
2810 		break;
2811 	case V_READ:
2812 		if (vp->v_rdcnt > 1)
2813 			return (V_TRUE);
2814 		break;
2815 	}
2816 
2817 	return (V_FALSE);
2818 }
2819 
2820 /*
2821  * vn_is_opened() checks whether a particular file is opened and
2822  * whether the open is for read and/or write.
2823  *
2824  * Vnode counts are only kept on regular files (v_type=VREG).
2825  */
2826 int
2827 vn_is_opened(
2828 	vnode_t *vp,
2829 	v_mode_t mode)
2830 {
2831 
2832 	ASSERT(vp != NULL);
2833 
2834 	switch (mode) {
2835 	case V_WRITE:
2836 		if (vp->v_wrcnt)
2837 			return (V_TRUE);
2838 		break;
2839 	case V_RDANDWR:
2840 		if (vp->v_rdcnt && vp->v_wrcnt)
2841 			return (V_TRUE);
2842 		break;
2843 	case V_RDORWR:
2844 		if (vp->v_rdcnt || vp->v_wrcnt)
2845 			return (V_TRUE);
2846 		break;
2847 	case V_READ:
2848 		if (vp->v_rdcnt)
2849 			return (V_TRUE);
2850 		break;
2851 	}
2852 
2853 	return (V_FALSE);
2854 }
2855 
2856 /*
2857  * vn_is_mapped() checks whether a particular file is mapped and whether
2858  * the file is mapped read and/or write.
2859  */
2860 int
2861 vn_is_mapped(
2862 	vnode_t *vp,
2863 	v_mode_t mode)
2864 {
2865 
2866 	ASSERT(vp != NULL);
2867 
2868 #if !defined(_LP64)
2869 	switch (mode) {
2870 	/*
2871 	 * The atomic_add_64_nv functions force atomicity in the
2872 	 * case of 32 bit architectures. Otherwise the 64 bit values
2873 	 * require two fetches. The value of the fields may be
2874 	 * (potentially) changed between the first fetch and the
2875 	 * second
2876 	 */
2877 	case V_WRITE:
2878 		if (atomic_add_64_nv((&(vp->v_mmap_write)), 0))
2879 			return (V_TRUE);
2880 		break;
2881 	case V_RDANDWR:
2882 		if ((atomic_add_64_nv((&(vp->v_mmap_read)), 0)) &&
2883 		    (atomic_add_64_nv((&(vp->v_mmap_write)), 0)))
2884 			return (V_TRUE);
2885 		break;
2886 	case V_RDORWR:
2887 		if ((atomic_add_64_nv((&(vp->v_mmap_read)), 0)) ||
2888 		    (atomic_add_64_nv((&(vp->v_mmap_write)), 0)))
2889 			return (V_TRUE);
2890 		break;
2891 	case V_READ:
2892 		if (atomic_add_64_nv((&(vp->v_mmap_read)), 0))
2893 			return (V_TRUE);
2894 		break;
2895 	}
2896 #else
2897 	switch (mode) {
2898 	case V_WRITE:
2899 		if (vp->v_mmap_write)
2900 			return (V_TRUE);
2901 		break;
2902 	case V_RDANDWR:
2903 		if (vp->v_mmap_read && vp->v_mmap_write)
2904 			return (V_TRUE);
2905 		break;
2906 	case V_RDORWR:
2907 		if (vp->v_mmap_read || vp->v_mmap_write)
2908 			return (V_TRUE);
2909 		break;
2910 	case V_READ:
2911 		if (vp->v_mmap_read)
2912 			return (V_TRUE);
2913 		break;
2914 	}
2915 #endif
2916 
2917 	return (V_FALSE);
2918 }
2919 
2920 /*
2921  * Set the operations vector for a vnode.
2922  *
2923  * FEM ensures that the v_femhead pointer is filled in before the
2924  * v_op pointer is changed.  This means that if the v_femhead pointer
2925  * is NULL, and the v_op field hasn't changed since before which checked
2926  * the v_femhead pointer; then our update is ok - we are not racing with
2927  * FEM.
2928  */
2929 void
2930 vn_setops(vnode_t *vp, vnodeops_t *vnodeops)
2931 {
2932 	vnodeops_t	*op;
2933 
2934 	ASSERT(vp != NULL);
2935 	ASSERT(vnodeops != NULL);
2936 
2937 	op = vp->v_op;
2938 	membar_consumer();
2939 	/*
2940 	 * If vp->v_femhead == NULL, then we'll call atomic_cas_ptr() to do
2941 	 * the compare-and-swap on vp->v_op.  If either fails, then FEM is
2942 	 * in effect on the vnode and we need to have FEM deal with it.
2943 	 */
2944 	if (vp->v_femhead != NULL || atomic_cas_ptr(&vp->v_op, op, vnodeops) !=
2945 	    op) {
2946 		fem_setvnops(vp, vnodeops);
2947 	}
2948 }
2949 
2950 /*
2951  * Retrieve the operations vector for a vnode
2952  * As with vn_setops(above); make sure we aren't racing with FEM.
2953  * FEM sets the v_op to a special, internal, vnodeops that wouldn't
2954  * make sense to the callers of this routine.
2955  */
2956 vnodeops_t *
2957 vn_getops(vnode_t *vp)
2958 {
2959 	vnodeops_t	*op;
2960 
2961 	ASSERT(vp != NULL);
2962 
2963 	op = vp->v_op;
2964 	membar_consumer();
2965 	if (vp->v_femhead == NULL && op == vp->v_op) {
2966 		return (op);
2967 	} else {
2968 		return (fem_getvnops(vp));
2969 	}
2970 }
2971 
2972 /*
2973  * Returns non-zero (1) if the vnodeops matches that of the vnode.
2974  * Returns zero (0) if not.
2975  */
2976 int
2977 vn_matchops(vnode_t *vp, vnodeops_t *vnodeops)
2978 {
2979 	return (vn_getops(vp) == vnodeops);
2980 }
2981 
2982 /*
2983  * Returns non-zero (1) if the specified operation matches the
2984  * corresponding operation for that the vnode.
2985  * Returns zero (0) if not.
2986  */
2987 
2988 #define	MATCHNAME(n1, n2) (((n1)[0] == (n2)[0]) && (strcmp((n1), (n2)) == 0))
2989 
2990 int
2991 vn_matchopval(vnode_t *vp, char *vopname, fs_generic_func_p funcp)
2992 {
2993 	const fs_operation_trans_def_t *otdp;
2994 	fs_generic_func_p *loc = NULL;
2995 	vnodeops_t	*vop = vn_getops(vp);
2996 
2997 	ASSERT(vopname != NULL);
2998 
2999 	for (otdp = vn_ops_table; otdp->name != NULL; otdp++) {
3000 		if (MATCHNAME(otdp->name, vopname)) {
3001 			loc = (fs_generic_func_p *)
3002 			    ((char *)(vop) + otdp->offset);
3003 			break;
3004 		}
3005 	}
3006 
3007 	return ((loc != NULL) && (*loc == funcp));
3008 }
3009 
3010 /*
3011  * fs_new_caller_id() needs to return a unique ID on a given local system.
3012  * The IDs do not need to survive across reboots.  These are primarily
3013  * used so that (FEM) monitors can detect particular callers (such as
3014  * the NFS server) to a given vnode/vfs operation.
3015  */
3016 u_longlong_t
3017 fs_new_caller_id()
3018 {
3019 	static uint64_t next_caller_id = 0LL; /* First call returns 1 */
3020 
3021 	return ((u_longlong_t)atomic_inc_64_nv(&next_caller_id));
3022 }
3023 
3024 /*
3025  * The value stored in v_path is relative to rootdir, located in the global
3026  * zone.  Zones or chroot environments which reside deeper inside the VFS
3027  * hierarchy will have a relative view of MAXPATHLEN since they are unaware of
3028  * what lies below their perceived root.  In order to keep v_path usable for
3029  * these child environments, its allocations are allowed to exceed MAXPATHLEN.
3030  *
3031  * An upper bound of max_vnode_path is placed upon v_path allocations to
3032  * prevent the system from going too wild at the behest of pathological
3033  * behavior from the operator.
3034  */
3035 size_t max_vnode_path = 4 * MAXPATHLEN;
3036 
3037 
3038 void
3039 vn_clearpath(vnode_t *vp, hrtime_t compare_stamp)
3040 {
3041 	char *buf;
3042 
3043 	mutex_enter(&vp->v_lock);
3044 	/*
3045 	 * If the snapshot of v_path_stamp passed in via compare_stamp does not
3046 	 * match the present value on the vnode, it indicates that subsequent
3047 	 * changes have occurred.  The v_path value is not cleared in this case
3048 	 * since the new value may be valid.
3049 	 */
3050 	if (compare_stamp != 0 && vp->v_path_stamp != compare_stamp) {
3051 		mutex_exit(&vp->v_lock);
3052 		return;
3053 	}
3054 	buf = vp->v_path;
3055 	vp->v_path = vn_vpath_empty;
3056 	vp->v_path_stamp = 0;
3057 	mutex_exit(&vp->v_lock);
3058 	if (buf != vn_vpath_empty) {
3059 		kmem_free(buf, strlen(buf) + 1);
3060 	}
3061 }
3062 
3063 static void
3064 vn_setpath_common(vnode_t *pvp, vnode_t *vp, const char *name, size_t len,
3065     boolean_t is_rename)
3066 {
3067 	char *buf, *oldbuf;
3068 	hrtime_t pstamp;
3069 	size_t baselen, buflen = 0;
3070 
3071 	/* Handle the vn_setpath_str case. */
3072 	if (pvp == NULL) {
3073 		if (len + 1 > max_vnode_path) {
3074 			DTRACE_PROBE4(vn__setpath__too__long, vnode_t *, pvp,
3075 			    vnode_t *, vp, char *, name, size_t, len + 1);
3076 			return;
3077 		}
3078 		buf = kmem_alloc(len + 1, KM_SLEEP);
3079 		bcopy(name, buf, len);
3080 		buf[len] = '\0';
3081 
3082 		mutex_enter(&vp->v_lock);
3083 		oldbuf = vp->v_path;
3084 		vp->v_path = buf;
3085 		vp->v_path_stamp = gethrtime();
3086 		mutex_exit(&vp->v_lock);
3087 		if (oldbuf != vn_vpath_empty) {
3088 			kmem_free(oldbuf, strlen(oldbuf) + 1);
3089 		}
3090 		return;
3091 	}
3092 
3093 	/* Take snapshot of parent dir */
3094 	mutex_enter(&pvp->v_lock);
3095 
3096 	if ((pvp->v_flag & VTRAVERSE) != 0) {
3097 		/*
3098 		 * When the parent vnode has VTRAVERSE set in its flags, normal
3099 		 * assumptions about v_path calculation no longer apply.  The
3100 		 * primary situation where this occurs is via the VFS tricks
3101 		 * which procfs plays in order to allow /proc/PID/(root|cwd) to
3102 		 * yield meaningful results.
3103 		 *
3104 		 * When this flag is set, v_path on the child must not be
3105 		 * updated since the calculated value is likely to be
3106 		 * incorrect, given the current context.
3107 		 */
3108 		mutex_exit(&pvp->v_lock);
3109 		return;
3110 	}
3111 
3112 retrybuf:
3113 	if (pvp->v_path == vn_vpath_empty) {
3114 		/*
3115 		 * Without v_path from the parent directory, generating a child
3116 		 * path from the name is impossible.
3117 		 */
3118 		if (len > 0) {
3119 			pstamp = pvp->v_path_stamp;
3120 			mutex_exit(&pvp->v_lock);
3121 			vn_clearpath(vp, pstamp);
3122 			return;
3123 		}
3124 
3125 		/*
3126 		 * The only feasible case here is where a NUL lookup is being
3127 		 * performed on rootdir prior to its v_path being populated.
3128 		 */
3129 		ASSERT(pvp->v_path_stamp == 0);
3130 		baselen = 0;
3131 		pstamp = 0;
3132 	} else {
3133 		pstamp = pvp->v_path_stamp;
3134 		baselen = strlen(pvp->v_path);
3135 		/* ignore a trailing slash if present */
3136 		if (pvp->v_path[baselen - 1] == '/') {
3137 			/* This should only the be case for rootdir */
3138 			ASSERT(baselen == 1 && pvp == rootdir);
3139 			baselen--;
3140 		}
3141 	}
3142 	mutex_exit(&pvp->v_lock);
3143 
3144 	if (buflen != 0) {
3145 		/* Free the existing (mis-sized) buffer in case of retry */
3146 		kmem_free(buf, buflen);
3147 	}
3148 	/* base, '/', name and trailing NUL */
3149 	buflen = baselen + len + 2;
3150 	if (buflen > max_vnode_path) {
3151 		DTRACE_PROBE4(vn__setpath_too__long, vnode_t *, pvp,
3152 		    vnode_t *, vp, char *, name, size_t, buflen);
3153 		return;
3154 	}
3155 	buf = kmem_alloc(buflen, KM_SLEEP);
3156 
3157 	mutex_enter(&pvp->v_lock);
3158 	if (pvp->v_path_stamp != pstamp) {
3159 		size_t vlen;
3160 
3161 		/*
3162 		 * Since v_path_stamp changed on the parent, it is likely that
3163 		 * v_path has been altered as well.  If the length does not
3164 		 * exactly match what was previously measured, the buffer
3165 		 * allocation must be repeated for proper sizing.
3166 		 */
3167 		if (pvp->v_path == vn_vpath_empty) {
3168 			/* Give up if parent lack v_path */
3169 			mutex_exit(&pvp->v_lock);
3170 			kmem_free(buf, buflen);
3171 			return;
3172 		}
3173 		vlen = strlen(pvp->v_path);
3174 		if (pvp->v_path[vlen - 1] == '/') {
3175 			vlen--;
3176 		}
3177 		if (vlen != baselen) {
3178 			goto retrybuf;
3179 		}
3180 	}
3181 	bcopy(pvp->v_path, buf, baselen);
3182 	mutex_exit(&pvp->v_lock);
3183 
3184 	buf[baselen] = '/';
3185 	baselen++;
3186 	bcopy(name, &buf[baselen], len + 1);
3187 
3188 	mutex_enter(&vp->v_lock);
3189 	if (vp->v_path_stamp == 0) {
3190 		/* never-visited vnode can inherit stamp from parent */
3191 		ASSERT(vp->v_path == vn_vpath_empty);
3192 		vp->v_path_stamp = pstamp;
3193 		vp->v_path = buf;
3194 		mutex_exit(&vp->v_lock);
3195 	} else if (vp->v_path_stamp < pstamp || is_rename) {
3196 		/*
3197 		 * Install the updated path and stamp, ensuring that the v_path
3198 		 * pointer is valid at all times for dtrace.
3199 		 */
3200 		oldbuf = vp->v_path;
3201 		vp->v_path = buf;
3202 		vp->v_path_stamp = gethrtime();
3203 		mutex_exit(&vp->v_lock);
3204 		kmem_free(oldbuf, strlen(oldbuf) + 1);
3205 	} else {
3206 		/*
3207 		 * If the timestamp matches or is greater, it means another
3208 		 * thread performed the update first while locks were dropped
3209 		 * here to make the allocation.  We defer to the newer value.
3210 		 */
3211 		mutex_exit(&vp->v_lock);
3212 		kmem_free(buf, buflen);
3213 	}
3214 	ASSERT(MUTEX_NOT_HELD(&vp->v_lock));
3215 }
3216 
3217 void
3218 vn_updatepath(vnode_t *pvp, vnode_t *vp, const char *name)
3219 {
3220 	size_t len;
3221 
3222 	/*
3223 	 * If the parent is older or empty, there's nothing further to do.
3224 	 */
3225 	if (pvp->v_path == vn_vpath_empty ||
3226 	    pvp->v_path_stamp <= vp->v_path_stamp) {
3227 		return;
3228 	}
3229 
3230 	/*
3231 	 * Given the lack of appropriate context, meaningful updates to v_path
3232 	 * cannot be made for during lookups for the '.' or '..' entries.
3233 	 */
3234 	len = strlen(name);
3235 	if (len == 0 || (len == 1 && name[0] == '.') ||
3236 	    (len == 2 && name[0] == '.' && name[1] == '.')) {
3237 		return;
3238 	}
3239 
3240 	vn_setpath_common(pvp, vp, name, len, B_FALSE);
3241 }
3242 
3243 /*
3244  * Given a starting vnode and a path, updates the path in the target vnode in
3245  * a safe manner.  If the vnode already has path information embedded, then the
3246  * cached path is left untouched.
3247  */
3248 /* ARGSUSED */
3249 void
3250 vn_setpath(vnode_t *rootvp, vnode_t *pvp, vnode_t *vp, const char *name,
3251     size_t len)
3252 {
3253 	vn_setpath_common(pvp, vp, name, len, B_FALSE);
3254 }
3255 
3256 /*
3257  * Sets the path to the vnode to be the given string, regardless of current
3258  * context.  The string must be a complete path from rootdir.  This is only used
3259  * by fsop_root() for setting the path based on the mountpoint.
3260  */
3261 void
3262 vn_setpath_str(vnode_t *vp, const char *str, size_t len)
3263 {
3264 	vn_setpath_common(NULL, vp, str, len, B_FALSE);
3265 }
3266 
3267 /*
3268  * Called from within filesystem's vop_rename() to handle renames once the
3269  * target vnode is available.
3270  */
3271 void
3272 vn_renamepath(vnode_t *pvp, vnode_t *vp, const char *name, size_t len)
3273 {
3274 	vn_setpath_common(pvp, vp, name, len, B_TRUE);
3275 }
3276 
3277 /*
3278  * Similar to vn_setpath_str(), this function sets the path of the destination
3279  * vnode to the be the same as the source vnode.
3280  */
3281 void
3282 vn_copypath(struct vnode *src, struct vnode *dst)
3283 {
3284 	char *buf;
3285 	hrtime_t stamp;
3286 	size_t buflen;
3287 
3288 	mutex_enter(&src->v_lock);
3289 	if (src->v_path == vn_vpath_empty) {
3290 		mutex_exit(&src->v_lock);
3291 		return;
3292 	}
3293 	buflen = strlen(src->v_path) + 1;
3294 	mutex_exit(&src->v_lock);
3295 
3296 	buf = kmem_alloc(buflen, KM_SLEEP);
3297 
3298 	mutex_enter(&src->v_lock);
3299 	if (src->v_path == vn_vpath_empty ||
3300 	    strlen(src->v_path) + 1 != buflen) {
3301 		mutex_exit(&src->v_lock);
3302 		kmem_free(buf, buflen);
3303 		return;
3304 	}
3305 	bcopy(src->v_path, buf, buflen);
3306 	stamp = src->v_path_stamp;
3307 	mutex_exit(&src->v_lock);
3308 
3309 	mutex_enter(&dst->v_lock);
3310 	if (dst->v_path != vn_vpath_empty) {
3311 		mutex_exit(&dst->v_lock);
3312 		kmem_free(buf, buflen);
3313 		return;
3314 	}
3315 	dst->v_path = buf;
3316 	dst->v_path_stamp = stamp;
3317 	mutex_exit(&dst->v_lock);
3318 }
3319 
3320 
3321 /*
3322  * XXX Private interface for segvn routines that handle vnode
3323  * large page segments.
3324  *
3325  * return 1 if vp's file system VOP_PAGEIO() implementation
3326  * can be safely used instead of VOP_GETPAGE() for handling
3327  * pagefaults against regular non swap files. VOP_PAGEIO()
3328  * interface is considered safe here if its implementation
3329  * is very close to VOP_GETPAGE() implementation.
3330  * e.g. It zero's out the part of the page beyond EOF. Doesn't
3331  * panic if there're file holes but instead returns an error.
3332  * Doesn't assume file won't be changed by user writes, etc.
3333  *
3334  * return 0 otherwise.
3335  *
3336  * For now allow segvn to only use VOP_PAGEIO() with ufs and nfs.
3337  */
3338 int
3339 vn_vmpss_usepageio(vnode_t *vp)
3340 {
3341 	vfs_t   *vfsp = vp->v_vfsp;
3342 	char *fsname = vfssw[vfsp->vfs_fstype].vsw_name;
3343 	char *pageio_ok_fss[] = {"ufs", "nfs", NULL};
3344 	char **fsok = pageio_ok_fss;
3345 
3346 	if (fsname == NULL) {
3347 		return (0);
3348 	}
3349 
3350 	for (; *fsok; fsok++) {
3351 		if (strcmp(*fsok, fsname) == 0) {
3352 			return (1);
3353 		}
3354 	}
3355 	return (0);
3356 }
3357 
3358 /* VOP_XXX() macros call the corresponding fop_xxx() function */
3359 
3360 int
3361 fop_open(
3362 	vnode_t **vpp,
3363 	int mode,
3364 	cred_t *cr,
3365 	caller_context_t *ct)
3366 {
3367 	int ret;
3368 	vnode_t *vp = *vpp;
3369 
3370 	VN_HOLD(vp);
3371 	/*
3372 	 * Adding to the vnode counts before calling open
3373 	 * avoids the need for a mutex. It circumvents a race
3374 	 * condition where a query made on the vnode counts results in a
3375 	 * false negative. The inquirer goes away believing the file is
3376 	 * not open when there is an open on the file already under way.
3377 	 *
3378 	 * The counts are meant to prevent NFS from granting a delegation
3379 	 * when it would be dangerous to do so.
3380 	 *
3381 	 * The vnode counts are only kept on regular files
3382 	 */
3383 	if ((*vpp)->v_type == VREG) {
3384 		if (mode & FREAD)
3385 			atomic_inc_32(&(*vpp)->v_rdcnt);
3386 		if (mode & FWRITE)
3387 			atomic_inc_32(&(*vpp)->v_wrcnt);
3388 	}
3389 
3390 	VOPXID_MAP_CR(vp, cr);
3391 
3392 	ret = (*(*(vpp))->v_op->vop_open)(vpp, mode, cr, ct);
3393 
3394 	if (ret) {
3395 		/*
3396 		 * Use the saved vp just in case the vnode ptr got trashed
3397 		 * by the error.
3398 		 */
3399 		VOPSTATS_UPDATE(vp, open);
3400 		if ((vp->v_type == VREG) && (mode & FREAD))
3401 			atomic_dec_32(&vp->v_rdcnt);
3402 		if ((vp->v_type == VREG) && (mode & FWRITE))
3403 			atomic_dec_32(&vp->v_wrcnt);
3404 	} else {
3405 		/*
3406 		 * Some filesystems will return a different vnode,
3407 		 * but the same path was still used to open it.
3408 		 * So if we do change the vnode and need to
3409 		 * copy over the path, do so here, rather than special
3410 		 * casing each filesystem. Adjust the vnode counts to
3411 		 * reflect the vnode switch.
3412 		 */
3413 		VOPSTATS_UPDATE(*vpp, open);
3414 		if (*vpp != vp) {
3415 			vn_copypath(vp, *vpp);
3416 			if (((*vpp)->v_type == VREG) && (mode & FREAD))
3417 				atomic_inc_32(&(*vpp)->v_rdcnt);
3418 			if ((vp->v_type == VREG) && (mode & FREAD))
3419 				atomic_dec_32(&vp->v_rdcnt);
3420 			if (((*vpp)->v_type == VREG) && (mode & FWRITE))
3421 				atomic_inc_32(&(*vpp)->v_wrcnt);
3422 			if ((vp->v_type == VREG) && (mode & FWRITE))
3423 				atomic_dec_32(&vp->v_wrcnt);
3424 		}
3425 	}
3426 	VN_RELE(vp);
3427 	return (ret);
3428 }
3429 
3430 int
3431 fop_close(
3432 	vnode_t *vp,
3433 	int flag,
3434 	int count,
3435 	offset_t offset,
3436 	cred_t *cr,
3437 	caller_context_t *ct)
3438 {
3439 	int err;
3440 
3441 	VOPXID_MAP_CR(vp, cr);
3442 
3443 	err = (*(vp)->v_op->vop_close)(vp, flag, count, offset, cr, ct);
3444 	VOPSTATS_UPDATE(vp, close);
3445 	/*
3446 	 * Check passed in count to handle possible dups. Vnode counts are only
3447 	 * kept on regular files
3448 	 */
3449 	if ((vp->v_type == VREG) && (count == 1))  {
3450 		if (flag & FREAD) {
3451 			ASSERT(vp->v_rdcnt > 0);
3452 			atomic_dec_32(&vp->v_rdcnt);
3453 		}
3454 		if (flag & FWRITE) {
3455 			ASSERT(vp->v_wrcnt > 0);
3456 			atomic_dec_32(&vp->v_wrcnt);
3457 		}
3458 	}
3459 	return (err);
3460 }
3461 
3462 int
3463 fop_read(
3464 	vnode_t *vp,
3465 	uio_t *uiop,
3466 	int ioflag,
3467 	cred_t *cr,
3468 	caller_context_t *ct)
3469 {
3470 	int	err;
3471 	ssize_t	resid_start = uiop->uio_resid;
3472 
3473 	VOPXID_MAP_CR(vp, cr);
3474 
3475 	err = (*(vp)->v_op->vop_read)(vp, uiop, ioflag, cr, ct);
3476 	VOPSTATS_UPDATE_IO(vp, read,
3477 	    read_bytes, (resid_start - uiop->uio_resid));
3478 	return (err);
3479 }
3480 
3481 int
3482 fop_write(
3483 	vnode_t *vp,
3484 	uio_t *uiop,
3485 	int ioflag,
3486 	cred_t *cr,
3487 	caller_context_t *ct)
3488 {
3489 	int	err;
3490 	ssize_t	resid_start = uiop->uio_resid;
3491 
3492 	VOPXID_MAP_CR(vp, cr);
3493 
3494 	err = (*(vp)->v_op->vop_write)(vp, uiop, ioflag, cr, ct);
3495 	VOPSTATS_UPDATE_IO(vp, write,
3496 	    write_bytes, (resid_start - uiop->uio_resid));
3497 	return (err);
3498 }
3499 
3500 int
3501 fop_ioctl(
3502 	vnode_t *vp,
3503 	int cmd,
3504 	intptr_t arg,
3505 	int flag,
3506 	cred_t *cr,
3507 	int *rvalp,
3508 	caller_context_t *ct)
3509 {
3510 	int	err;
3511 
3512 	VOPXID_MAP_CR(vp, cr);
3513 
3514 	err = (*(vp)->v_op->vop_ioctl)(vp, cmd, arg, flag, cr, rvalp, ct);
3515 	VOPSTATS_UPDATE(vp, ioctl);
3516 	return (err);
3517 }
3518 
3519 int
3520 fop_setfl(
3521 	vnode_t *vp,
3522 	int oflags,
3523 	int nflags,
3524 	cred_t *cr,
3525 	caller_context_t *ct)
3526 {
3527 	int	err;
3528 
3529 	VOPXID_MAP_CR(vp, cr);
3530 
3531 	err = (*(vp)->v_op->vop_setfl)(vp, oflags, nflags, cr, ct);
3532 	VOPSTATS_UPDATE(vp, setfl);
3533 	return (err);
3534 }
3535 
3536 int
3537 fop_getattr(
3538 	vnode_t *vp,
3539 	vattr_t *vap,
3540 	int flags,
3541 	cred_t *cr,
3542 	caller_context_t *ct)
3543 {
3544 	int	err;
3545 
3546 	VOPXID_MAP_CR(vp, cr);
3547 
3548 	/*
3549 	 * If this file system doesn't understand the xvattr extensions
3550 	 * then turn off the xvattr bit.
3551 	 */
3552 	if (vfs_has_feature(vp->v_vfsp, VFSFT_XVATTR) == 0) {
3553 		vap->va_mask &= ~AT_XVATTR;
3554 	}
3555 
3556 	/*
3557 	 * We're only allowed to skip the ACL check iff we used a 32 bit
3558 	 * ACE mask with VOP_ACCESS() to determine permissions.
3559 	 */
3560 	if ((flags & ATTR_NOACLCHECK) &&
3561 	    vfs_has_feature(vp->v_vfsp, VFSFT_ACEMASKONACCESS) == 0) {
3562 		return (EINVAL);
3563 	}
3564 	err = (*(vp)->v_op->vop_getattr)(vp, vap, flags, cr, ct);
3565 	VOPSTATS_UPDATE(vp, getattr);
3566 	return (err);
3567 }
3568 
3569 int
3570 fop_setattr(
3571 	vnode_t *vp,
3572 	vattr_t *vap,
3573 	int flags,
3574 	cred_t *cr,
3575 	caller_context_t *ct)
3576 {
3577 	int	err;
3578 
3579 	VOPXID_MAP_CR(vp, cr);
3580 
3581 	/*
3582 	 * If this file system doesn't understand the xvattr extensions
3583 	 * then turn off the xvattr bit.
3584 	 */
3585 	if (vfs_has_feature(vp->v_vfsp, VFSFT_XVATTR) == 0) {
3586 		vap->va_mask &= ~AT_XVATTR;
3587 	}
3588 
3589 	/*
3590 	 * We're only allowed to skip the ACL check iff we used a 32 bit
3591 	 * ACE mask with VOP_ACCESS() to determine permissions.
3592 	 */
3593 	if ((flags & ATTR_NOACLCHECK) &&
3594 	    vfs_has_feature(vp->v_vfsp, VFSFT_ACEMASKONACCESS) == 0) {
3595 		return (EINVAL);
3596 	}
3597 	err = (*(vp)->v_op->vop_setattr)(vp, vap, flags, cr, ct);
3598 	VOPSTATS_UPDATE(vp, setattr);
3599 	return (err);
3600 }
3601 
3602 int
3603 fop_access(
3604 	vnode_t *vp,
3605 	int mode,
3606 	int flags,
3607 	cred_t *cr,
3608 	caller_context_t *ct)
3609 {
3610 	int	err;
3611 
3612 	if ((flags & V_ACE_MASK) &&
3613 	    vfs_has_feature(vp->v_vfsp, VFSFT_ACEMASKONACCESS) == 0) {
3614 		return (EINVAL);
3615 	}
3616 
3617 	VOPXID_MAP_CR(vp, cr);
3618 
3619 	err = (*(vp)->v_op->vop_access)(vp, mode, flags, cr, ct);
3620 	VOPSTATS_UPDATE(vp, access);
3621 	return (err);
3622 }
3623 
3624 int
3625 fop_lookup(
3626 	vnode_t *dvp,
3627 	char *nm,
3628 	vnode_t **vpp,
3629 	pathname_t *pnp,
3630 	int flags,
3631 	vnode_t *rdir,
3632 	cred_t *cr,
3633 	caller_context_t *ct,
3634 	int *deflags,		/* Returned per-dirent flags */
3635 	pathname_t *ppnp)	/* Returned case-preserved name in directory */
3636 {
3637 	int ret;
3638 
3639 	/*
3640 	 * If this file system doesn't support case-insensitive access
3641 	 * and said access is requested, fail quickly.  It is required
3642 	 * that if the vfs supports case-insensitive lookup, it also
3643 	 * supports extended dirent flags.
3644 	 */
3645 	if (flags & FIGNORECASE &&
3646 	    (vfs_has_feature(dvp->v_vfsp, VFSFT_CASEINSENSITIVE) == 0 &&
3647 	    vfs_has_feature(dvp->v_vfsp, VFSFT_NOCASESENSITIVE) == 0))
3648 		return (EINVAL);
3649 
3650 	VOPXID_MAP_CR(dvp, cr);
3651 
3652 	if ((flags & LOOKUP_XATTR) && (flags & LOOKUP_HAVE_SYSATTR_DIR) == 0) {
3653 		ret = xattr_dir_lookup(dvp, vpp, flags, cr);
3654 	} else {
3655 		ret = (*(dvp)->v_op->vop_lookup)
3656 		    (dvp, nm, vpp, pnp, flags, rdir, cr, ct, deflags, ppnp);
3657 	}
3658 	if (ret == 0 && *vpp) {
3659 		VOPSTATS_UPDATE(*vpp, lookup);
3660 		vn_updatepath(dvp, *vpp, nm);
3661 	}
3662 
3663 	return (ret);
3664 }
3665 
3666 int
3667 fop_create(
3668 	vnode_t *dvp,
3669 	char *name,
3670 	vattr_t *vap,
3671 	vcexcl_t excl,
3672 	int mode,
3673 	vnode_t **vpp,
3674 	cred_t *cr,
3675 	int flags,
3676 	caller_context_t *ct,
3677 	vsecattr_t *vsecp)	/* ACL to set during create */
3678 {
3679 	int ret;
3680 
3681 	if (vsecp != NULL &&
3682 	    vfs_has_feature(dvp->v_vfsp, VFSFT_ACLONCREATE) == 0) {
3683 		return (EINVAL);
3684 	}
3685 	/*
3686 	 * If this file system doesn't support case-insensitive access
3687 	 * and said access is requested, fail quickly.
3688 	 */
3689 	if (flags & FIGNORECASE &&
3690 	    (vfs_has_feature(dvp->v_vfsp, VFSFT_CASEINSENSITIVE) == 0 &&
3691 	    vfs_has_feature(dvp->v_vfsp, VFSFT_NOCASESENSITIVE) == 0))
3692 		return (EINVAL);
3693 
3694 	VOPXID_MAP_CR(dvp, cr);
3695 
3696 	ret = (*(dvp)->v_op->vop_create)
3697 	    (dvp, name, vap, excl, mode, vpp, cr, flags, ct, vsecp);
3698 	if (ret == 0 && *vpp) {
3699 		VOPSTATS_UPDATE(*vpp, create);
3700 		vn_updatepath(dvp, *vpp, name);
3701 	}
3702 
3703 	return (ret);
3704 }
3705 
3706 int
3707 fop_remove(
3708 	vnode_t *dvp,
3709 	char *nm,
3710 	cred_t *cr,
3711 	caller_context_t *ct,
3712 	int flags)
3713 {
3714 	int	err;
3715 
3716 	/*
3717 	 * If this file system doesn't support case-insensitive access
3718 	 * and said access is requested, fail quickly.
3719 	 */
3720 	if (flags & FIGNORECASE &&
3721 	    (vfs_has_feature(dvp->v_vfsp, VFSFT_CASEINSENSITIVE) == 0 &&
3722 	    vfs_has_feature(dvp->v_vfsp, VFSFT_NOCASESENSITIVE) == 0))
3723 		return (EINVAL);
3724 
3725 	VOPXID_MAP_CR(dvp, cr);
3726 
3727 	err = (*(dvp)->v_op->vop_remove)(dvp, nm, cr, ct, flags);
3728 	VOPSTATS_UPDATE(dvp, remove);
3729 	return (err);
3730 }
3731 
3732 int
3733 fop_link(
3734 	vnode_t *tdvp,
3735 	vnode_t *svp,
3736 	char *tnm,
3737 	cred_t *cr,
3738 	caller_context_t *ct,
3739 	int flags)
3740 {
3741 	int	err;
3742 
3743 	/*
3744 	 * If the target file system doesn't support case-insensitive access
3745 	 * and said access is requested, fail quickly.
3746 	 */
3747 	if (flags & FIGNORECASE &&
3748 	    (vfs_has_feature(tdvp->v_vfsp, VFSFT_CASEINSENSITIVE) == 0 &&
3749 	    vfs_has_feature(tdvp->v_vfsp, VFSFT_NOCASESENSITIVE) == 0))
3750 		return (EINVAL);
3751 
3752 	VOPXID_MAP_CR(tdvp, cr);
3753 
3754 	err = (*(tdvp)->v_op->vop_link)(tdvp, svp, tnm, cr, ct, flags);
3755 	VOPSTATS_UPDATE(tdvp, link);
3756 	return (err);
3757 }
3758 
3759 int
3760 fop_rename(
3761 	vnode_t *sdvp,
3762 	char *snm,
3763 	vnode_t *tdvp,
3764 	char *tnm,
3765 	cred_t *cr,
3766 	caller_context_t *ct,
3767 	int flags)
3768 {
3769 	int	err;
3770 
3771 	/*
3772 	 * If the file system involved does not support
3773 	 * case-insensitive access and said access is requested, fail
3774 	 * quickly.
3775 	 */
3776 	if (flags & FIGNORECASE &&
3777 	    ((vfs_has_feature(sdvp->v_vfsp, VFSFT_CASEINSENSITIVE) == 0 &&
3778 	    vfs_has_feature(sdvp->v_vfsp, VFSFT_NOCASESENSITIVE) == 0)))
3779 		return (EINVAL);
3780 
3781 	VOPXID_MAP_CR(tdvp, cr);
3782 
3783 	err = (*(sdvp)->v_op->vop_rename)(sdvp, snm, tdvp, tnm, cr, ct, flags);
3784 	VOPSTATS_UPDATE(sdvp, rename);
3785 	return (err);
3786 }
3787 
3788 int
3789 fop_mkdir(
3790 	vnode_t *dvp,
3791 	char *dirname,
3792 	vattr_t *vap,
3793 	vnode_t **vpp,
3794 	cred_t *cr,
3795 	caller_context_t *ct,
3796 	int flags,
3797 	vsecattr_t *vsecp)	/* ACL to set during create */
3798 {
3799 	int ret;
3800 
3801 	if (vsecp != NULL &&
3802 	    vfs_has_feature(dvp->v_vfsp, VFSFT_ACLONCREATE) == 0) {
3803 		return (EINVAL);
3804 	}
3805 	/*
3806 	 * If this file system doesn't support case-insensitive access
3807 	 * and said access is requested, fail quickly.
3808 	 */
3809 	if (flags & FIGNORECASE &&
3810 	    (vfs_has_feature(dvp->v_vfsp, VFSFT_CASEINSENSITIVE) == 0 &&
3811 	    vfs_has_feature(dvp->v_vfsp, VFSFT_NOCASESENSITIVE) == 0))
3812 		return (EINVAL);
3813 
3814 	VOPXID_MAP_CR(dvp, cr);
3815 
3816 	ret = (*(dvp)->v_op->vop_mkdir)
3817 	    (dvp, dirname, vap, vpp, cr, ct, flags, vsecp);
3818 	if (ret == 0 && *vpp) {
3819 		VOPSTATS_UPDATE(*vpp, mkdir);
3820 		vn_updatepath(dvp, *vpp, dirname);
3821 	}
3822 
3823 	return (ret);
3824 }
3825 
3826 int
3827 fop_rmdir(
3828 	vnode_t *dvp,
3829 	char *nm,
3830 	vnode_t *cdir,
3831 	cred_t *cr,
3832 	caller_context_t *ct,
3833 	int flags)
3834 {
3835 	int	err;
3836 
3837 	/*
3838 	 * If this file system doesn't support case-insensitive access
3839 	 * and said access is requested, fail quickly.
3840 	 */
3841 	if (flags & FIGNORECASE &&
3842 	    (vfs_has_feature(dvp->v_vfsp, VFSFT_CASEINSENSITIVE) == 0 &&
3843 	    vfs_has_feature(dvp->v_vfsp, VFSFT_NOCASESENSITIVE) == 0))
3844 		return (EINVAL);
3845 
3846 	VOPXID_MAP_CR(dvp, cr);
3847 
3848 	err = (*(dvp)->v_op->vop_rmdir)(dvp, nm, cdir, cr, ct, flags);
3849 	VOPSTATS_UPDATE(dvp, rmdir);
3850 	return (err);
3851 }
3852 
3853 int
3854 fop_readdir(
3855 	vnode_t *vp,
3856 	uio_t *uiop,
3857 	cred_t *cr,
3858 	int *eofp,
3859 	caller_context_t *ct,
3860 	int flags)
3861 {
3862 	int	err;
3863 	ssize_t	resid_start = uiop->uio_resid;
3864 
3865 	/*
3866 	 * If this file system doesn't support retrieving directory
3867 	 * entry flags and said access is requested, fail quickly.
3868 	 */
3869 	if (flags & V_RDDIR_ENTFLAGS &&
3870 	    vfs_has_feature(vp->v_vfsp, VFSFT_DIRENTFLAGS) == 0)
3871 		return (EINVAL);
3872 
3873 	VOPXID_MAP_CR(vp, cr);
3874 
3875 	err = (*(vp)->v_op->vop_readdir)(vp, uiop, cr, eofp, ct, flags);
3876 	VOPSTATS_UPDATE_IO(vp, readdir,
3877 	    readdir_bytes, (resid_start - uiop->uio_resid));
3878 	return (err);
3879 }
3880 
3881 int
3882 fop_symlink(
3883 	vnode_t *dvp,
3884 	char *linkname,
3885 	vattr_t *vap,
3886 	char *target,
3887 	cred_t *cr,
3888 	caller_context_t *ct,
3889 	int flags)
3890 {
3891 	int	err;
3892 	xvattr_t xvattr;
3893 
3894 	/*
3895 	 * If this file system doesn't support case-insensitive access
3896 	 * and said access is requested, fail quickly.
3897 	 */
3898 	if (flags & FIGNORECASE &&
3899 	    (vfs_has_feature(dvp->v_vfsp, VFSFT_CASEINSENSITIVE) == 0 &&
3900 	    vfs_has_feature(dvp->v_vfsp, VFSFT_NOCASESENSITIVE) == 0))
3901 		return (EINVAL);
3902 
3903 	VOPXID_MAP_CR(dvp, cr);
3904 
3905 	/* check for reparse point */
3906 	if ((vfs_has_feature(dvp->v_vfsp, VFSFT_REPARSE)) &&
3907 	    (strncmp(target, FS_REPARSE_TAG_STR,
3908 	    strlen(FS_REPARSE_TAG_STR)) == 0)) {
3909 		if (!fs_reparse_mark(target, vap, &xvattr))
3910 			vap = (vattr_t *)&xvattr;
3911 	}
3912 
3913 	err = (*(dvp)->v_op->vop_symlink)
3914 	    (dvp, linkname, vap, target, cr, ct, flags);
3915 	VOPSTATS_UPDATE(dvp, symlink);
3916 	return (err);
3917 }
3918 
3919 int
3920 fop_readlink(
3921 	vnode_t *vp,
3922 	uio_t *uiop,
3923 	cred_t *cr,
3924 	caller_context_t *ct)
3925 {
3926 	int	err;
3927 
3928 	VOPXID_MAP_CR(vp, cr);
3929 
3930 	err = (*(vp)->v_op->vop_readlink)(vp, uiop, cr, ct);
3931 	VOPSTATS_UPDATE(vp, readlink);
3932 	return (err);
3933 }
3934 
3935 int
3936 fop_fsync(
3937 	vnode_t *vp,
3938 	int syncflag,
3939 	cred_t *cr,
3940 	caller_context_t *ct)
3941 {
3942 	int	err;
3943 
3944 	VOPXID_MAP_CR(vp, cr);
3945 
3946 	err = (*(vp)->v_op->vop_fsync)(vp, syncflag, cr, ct);
3947 	VOPSTATS_UPDATE(vp, fsync);
3948 	return (err);
3949 }
3950 
3951 void
3952 fop_inactive(
3953 	vnode_t *vp,
3954 	cred_t *cr,
3955 	caller_context_t *ct)
3956 {
3957 	/* Need to update stats before vop call since we may lose the vnode */
3958 	VOPSTATS_UPDATE(vp, inactive);
3959 
3960 	VOPXID_MAP_CR(vp, cr);
3961 
3962 	(*(vp)->v_op->vop_inactive)(vp, cr, ct);
3963 }
3964 
3965 int
3966 fop_fid(
3967 	vnode_t *vp,
3968 	fid_t *fidp,
3969 	caller_context_t *ct)
3970 {
3971 	int	err;
3972 
3973 	err = (*(vp)->v_op->vop_fid)(vp, fidp, ct);
3974 	VOPSTATS_UPDATE(vp, fid);
3975 	return (err);
3976 }
3977 
3978 int
3979 fop_rwlock(
3980 	vnode_t *vp,
3981 	int write_lock,
3982 	caller_context_t *ct)
3983 {
3984 	int	ret;
3985 
3986 	ret = ((*(vp)->v_op->vop_rwlock)(vp, write_lock, ct));
3987 	VOPSTATS_UPDATE(vp, rwlock);
3988 	return (ret);
3989 }
3990 
3991 void
3992 fop_rwunlock(
3993 	vnode_t *vp,
3994 	int write_lock,
3995 	caller_context_t *ct)
3996 {
3997 	(*(vp)->v_op->vop_rwunlock)(vp, write_lock, ct);
3998 	VOPSTATS_UPDATE(vp, rwunlock);
3999 }
4000 
4001 int
4002 fop_seek(
4003 	vnode_t *vp,
4004 	offset_t ooff,
4005 	offset_t *noffp,
4006 	caller_context_t *ct)
4007 {
4008 	int	err;
4009 
4010 	err = (*(vp)->v_op->vop_seek)(vp, ooff, noffp, ct);
4011 	VOPSTATS_UPDATE(vp, seek);
4012 	return (err);
4013 }
4014 
4015 int
4016 fop_cmp(
4017 	vnode_t *vp1,
4018 	vnode_t *vp2,
4019 	caller_context_t *ct)
4020 {
4021 	int	err;
4022 
4023 	err = (*(vp1)->v_op->vop_cmp)(vp1, vp2, ct);
4024 	VOPSTATS_UPDATE(vp1, cmp);
4025 	return (err);
4026 }
4027 
4028 int
4029 fop_frlock(
4030 	vnode_t *vp,
4031 	int cmd,
4032 	flock64_t *bfp,
4033 	int flag,
4034 	offset_t offset,
4035 	struct flk_callback *flk_cbp,
4036 	cred_t *cr,
4037 	caller_context_t *ct)
4038 {
4039 	int	err;
4040 
4041 	VOPXID_MAP_CR(vp, cr);
4042 
4043 	err = (*(vp)->v_op->vop_frlock)
4044 	    (vp, cmd, bfp, flag, offset, flk_cbp, cr, ct);
4045 	VOPSTATS_UPDATE(vp, frlock);
4046 	return (err);
4047 }
4048 
4049 int
4050 fop_space(
4051 	vnode_t *vp,
4052 	int cmd,
4053 	flock64_t *bfp,
4054 	int flag,
4055 	offset_t offset,
4056 	cred_t *cr,
4057 	caller_context_t *ct)
4058 {
4059 	int	err;
4060 
4061 	VOPXID_MAP_CR(vp, cr);
4062 
4063 	err = (*(vp)->v_op->vop_space)(vp, cmd, bfp, flag, offset, cr, ct);
4064 	VOPSTATS_UPDATE(vp, space);
4065 	return (err);
4066 }
4067 
4068 int
4069 fop_realvp(
4070 	vnode_t *vp,
4071 	vnode_t **vpp,
4072 	caller_context_t *ct)
4073 {
4074 	int	err;
4075 
4076 	err = (*(vp)->v_op->vop_realvp)(vp, vpp, ct);
4077 	VOPSTATS_UPDATE(vp, realvp);
4078 	return (err);
4079 }
4080 
4081 int
4082 fop_getpage(
4083 	vnode_t *vp,
4084 	offset_t off,
4085 	size_t len,
4086 	uint_t *protp,
4087 	page_t **plarr,
4088 	size_t plsz,
4089 	struct seg *seg,
4090 	caddr_t addr,
4091 	enum seg_rw rw,
4092 	cred_t *cr,
4093 	caller_context_t *ct)
4094 {
4095 	int	err;
4096 
4097 	VOPXID_MAP_CR(vp, cr);
4098 
4099 	err = (*(vp)->v_op->vop_getpage)
4100 	    (vp, off, len, protp, plarr, plsz, seg, addr, rw, cr, ct);
4101 	VOPSTATS_UPDATE(vp, getpage);
4102 	return (err);
4103 }
4104 
4105 int
4106 fop_putpage(
4107 	vnode_t *vp,
4108 	offset_t off,
4109 	size_t len,
4110 	int flags,
4111 	cred_t *cr,
4112 	caller_context_t *ct)
4113 {
4114 	int	err;
4115 
4116 	VOPXID_MAP_CR(vp, cr);
4117 
4118 	err = (*(vp)->v_op->vop_putpage)(vp, off, len, flags, cr, ct);
4119 	VOPSTATS_UPDATE(vp, putpage);
4120 	return (err);
4121 }
4122 
4123 int
4124 fop_map(
4125 	vnode_t *vp,
4126 	offset_t off,
4127 	struct as *as,
4128 	caddr_t *addrp,
4129 	size_t len,
4130 	uchar_t prot,
4131 	uchar_t maxprot,
4132 	uint_t flags,
4133 	cred_t *cr,
4134 	caller_context_t *ct)
4135 {
4136 	int	err;
4137 
4138 	VOPXID_MAP_CR(vp, cr);
4139 
4140 	err = (*(vp)->v_op->vop_map)
4141 	    (vp, off, as, addrp, len, prot, maxprot, flags, cr, ct);
4142 	VOPSTATS_UPDATE(vp, map);
4143 	return (err);
4144 }
4145 
4146 int
4147 fop_addmap(
4148 	vnode_t *vp,
4149 	offset_t off,
4150 	struct as *as,
4151 	caddr_t addr,
4152 	size_t len,
4153 	uchar_t prot,
4154 	uchar_t maxprot,
4155 	uint_t flags,
4156 	cred_t *cr,
4157 	caller_context_t *ct)
4158 {
4159 	int error;
4160 	u_longlong_t delta;
4161 
4162 	VOPXID_MAP_CR(vp, cr);
4163 
4164 	error = (*(vp)->v_op->vop_addmap)
4165 	    (vp, off, as, addr, len, prot, maxprot, flags, cr, ct);
4166 
4167 	if ((!error) && (vp->v_type == VREG)) {
4168 		delta = (u_longlong_t)btopr(len);
4169 		/*
4170 		 * If file is declared MAP_PRIVATE, it can't be written back
4171 		 * even if open for write. Handle as read.
4172 		 */
4173 		if (flags & MAP_PRIVATE) {
4174 			atomic_add_64((uint64_t *)(&(vp->v_mmap_read)),
4175 			    (int64_t)delta);
4176 		} else {
4177 			/*
4178 			 * atomic_add_64 forces the fetch of a 64 bit value to
4179 			 * be atomic on 32 bit machines
4180 			 */
4181 			if (maxprot & PROT_WRITE)
4182 				atomic_add_64((uint64_t *)(&(vp->v_mmap_write)),
4183 				    (int64_t)delta);
4184 			if (maxprot & PROT_READ)
4185 				atomic_add_64((uint64_t *)(&(vp->v_mmap_read)),
4186 				    (int64_t)delta);
4187 			if (maxprot & PROT_EXEC)
4188 				atomic_add_64((uint64_t *)(&(vp->v_mmap_read)),
4189 				    (int64_t)delta);
4190 		}
4191 	}
4192 	VOPSTATS_UPDATE(vp, addmap);
4193 	return (error);
4194 }
4195 
4196 int
4197 fop_delmap(
4198 	vnode_t *vp,
4199 	offset_t off,
4200 	struct as *as,
4201 	caddr_t addr,
4202 	size_t len,
4203 	uint_t prot,
4204 	uint_t maxprot,
4205 	uint_t flags,
4206 	cred_t *cr,
4207 	caller_context_t *ct)
4208 {
4209 	int error;
4210 	u_longlong_t delta;
4211 
4212 	VOPXID_MAP_CR(vp, cr);
4213 
4214 	error = (*(vp)->v_op->vop_delmap)
4215 	    (vp, off, as, addr, len, prot, maxprot, flags, cr, ct);
4216 
4217 	/*
4218 	 * NFS calls into delmap twice, the first time
4219 	 * it simply establishes a callback mechanism and returns EAGAIN
4220 	 * while the real work is being done upon the second invocation.
4221 	 * We have to detect this here and only decrement the counts upon
4222 	 * the second delmap request.
4223 	 */
4224 	if ((error != EAGAIN) && (vp->v_type == VREG)) {
4225 
4226 		delta = (u_longlong_t)btopr(len);
4227 
4228 		if (flags & MAP_PRIVATE) {
4229 			atomic_add_64((uint64_t *)(&(vp->v_mmap_read)),
4230 			    (int64_t)(-delta));
4231 		} else {
4232 			/*
4233 			 * atomic_add_64 forces the fetch of a 64 bit value
4234 			 * to be atomic on 32 bit machines
4235 			 */
4236 			if (maxprot & PROT_WRITE)
4237 				atomic_add_64((uint64_t *)(&(vp->v_mmap_write)),
4238 				    (int64_t)(-delta));
4239 			if (maxprot & PROT_READ)
4240 				atomic_add_64((uint64_t *)(&(vp->v_mmap_read)),
4241 				    (int64_t)(-delta));
4242 			if (maxprot & PROT_EXEC)
4243 				atomic_add_64((uint64_t *)(&(vp->v_mmap_read)),
4244 				    (int64_t)(-delta));
4245 		}
4246 	}
4247 	VOPSTATS_UPDATE(vp, delmap);
4248 	return (error);
4249 }
4250 
4251 
4252 int
4253 fop_poll(
4254 	vnode_t *vp,
4255 	short events,
4256 	int anyyet,
4257 	short *reventsp,
4258 	struct pollhead **phpp,
4259 	caller_context_t *ct)
4260 {
4261 	int	err;
4262 
4263 	err = (*(vp)->v_op->vop_poll)(vp, events, anyyet, reventsp, phpp, ct);
4264 	VOPSTATS_UPDATE(vp, poll);
4265 	return (err);
4266 }
4267 
4268 int
4269 fop_dump(
4270 	vnode_t *vp,
4271 	caddr_t addr,
4272 	offset_t lbdn,
4273 	offset_t dblks,
4274 	caller_context_t *ct)
4275 {
4276 	int	err;
4277 
4278 	/* ensure lbdn and dblks can be passed safely to bdev_dump */
4279 	if ((lbdn != (daddr_t)lbdn) || (dblks != (int)dblks))
4280 		return (EIO);
4281 
4282 	err = (*(vp)->v_op->vop_dump)(vp, addr, lbdn, dblks, ct);
4283 	VOPSTATS_UPDATE(vp, dump);
4284 	return (err);
4285 }
4286 
4287 int
4288 fop_pathconf(
4289 	vnode_t *vp,
4290 	int cmd,
4291 	ulong_t *valp,
4292 	cred_t *cr,
4293 	caller_context_t *ct)
4294 {
4295 	int	err;
4296 
4297 	VOPXID_MAP_CR(vp, cr);
4298 
4299 	err = (*(vp)->v_op->vop_pathconf)(vp, cmd, valp, cr, ct);
4300 	VOPSTATS_UPDATE(vp, pathconf);
4301 	return (err);
4302 }
4303 
4304 int
4305 fop_pageio(
4306 	vnode_t *vp,
4307 	struct page *pp,
4308 	u_offset_t io_off,
4309 	size_t io_len,
4310 	int flags,
4311 	cred_t *cr,
4312 	caller_context_t *ct)
4313 {
4314 	int	err;
4315 
4316 	VOPXID_MAP_CR(vp, cr);
4317 
4318 	err = (*(vp)->v_op->vop_pageio)(vp, pp, io_off, io_len, flags, cr, ct);
4319 	VOPSTATS_UPDATE(vp, pageio);
4320 	return (err);
4321 }
4322 
4323 int
4324 fop_dumpctl(
4325 	vnode_t *vp,
4326 	int action,
4327 	offset_t *blkp,
4328 	caller_context_t *ct)
4329 {
4330 	int	err;
4331 	err = (*(vp)->v_op->vop_dumpctl)(vp, action, blkp, ct);
4332 	VOPSTATS_UPDATE(vp, dumpctl);
4333 	return (err);
4334 }
4335 
4336 void
4337 fop_dispose(
4338 	vnode_t *vp,
4339 	page_t *pp,
4340 	int flag,
4341 	int dn,
4342 	cred_t *cr,
4343 	caller_context_t *ct)
4344 {
4345 	/* Must do stats first since it's possible to lose the vnode */
4346 	VOPSTATS_UPDATE(vp, dispose);
4347 
4348 	VOPXID_MAP_CR(vp, cr);
4349 
4350 	(*(vp)->v_op->vop_dispose)(vp, pp, flag, dn, cr, ct);
4351 }
4352 
4353 int
4354 fop_setsecattr(
4355 	vnode_t *vp,
4356 	vsecattr_t *vsap,
4357 	int flag,
4358 	cred_t *cr,
4359 	caller_context_t *ct)
4360 {
4361 	int	err;
4362 
4363 	VOPXID_MAP_CR(vp, cr);
4364 
4365 	/*
4366 	 * We're only allowed to skip the ACL check iff we used a 32 bit
4367 	 * ACE mask with VOP_ACCESS() to determine permissions.
4368 	 */
4369 	if ((flag & ATTR_NOACLCHECK) &&
4370 	    vfs_has_feature(vp->v_vfsp, VFSFT_ACEMASKONACCESS) == 0) {
4371 		return (EINVAL);
4372 	}
4373 	err = (*(vp)->v_op->vop_setsecattr) (vp, vsap, flag, cr, ct);
4374 	VOPSTATS_UPDATE(vp, setsecattr);
4375 	return (err);
4376 }
4377 
4378 int
4379 fop_getsecattr(
4380 	vnode_t *vp,
4381 	vsecattr_t *vsap,
4382 	int flag,
4383 	cred_t *cr,
4384 	caller_context_t *ct)
4385 {
4386 	int	err;
4387 
4388 	/*
4389 	 * We're only allowed to skip the ACL check iff we used a 32 bit
4390 	 * ACE mask with VOP_ACCESS() to determine permissions.
4391 	 */
4392 	if ((flag & ATTR_NOACLCHECK) &&
4393 	    vfs_has_feature(vp->v_vfsp, VFSFT_ACEMASKONACCESS) == 0) {
4394 		return (EINVAL);
4395 	}
4396 
4397 	VOPXID_MAP_CR(vp, cr);
4398 
4399 	err = (*(vp)->v_op->vop_getsecattr) (vp, vsap, flag, cr, ct);
4400 	VOPSTATS_UPDATE(vp, getsecattr);
4401 	return (err);
4402 }
4403 
4404 int
4405 fop_shrlock(
4406 	vnode_t *vp,
4407 	int cmd,
4408 	struct shrlock *shr,
4409 	int flag,
4410 	cred_t *cr,
4411 	caller_context_t *ct)
4412 {
4413 	int	err;
4414 
4415 	VOPXID_MAP_CR(vp, cr);
4416 
4417 	err = (*(vp)->v_op->vop_shrlock)(vp, cmd, shr, flag, cr, ct);
4418 	VOPSTATS_UPDATE(vp, shrlock);
4419 	return (err);
4420 }
4421 
4422 int
4423 fop_vnevent(vnode_t *vp, vnevent_t vnevent, vnode_t *dvp, char *fnm,
4424     caller_context_t *ct)
4425 {
4426 	int	err;
4427 
4428 	err = (*(vp)->v_op->vop_vnevent)(vp, vnevent, dvp, fnm, ct);
4429 	VOPSTATS_UPDATE(vp, vnevent);
4430 	return (err);
4431 }
4432 
4433 int
4434 fop_reqzcbuf(vnode_t *vp, enum uio_rw ioflag, xuio_t *uiop, cred_t *cr,
4435     caller_context_t *ct)
4436 {
4437 	int err;
4438 
4439 	if (vfs_has_feature(vp->v_vfsp, VFSFT_ZEROCOPY_SUPPORTED) == 0)
4440 		return (ENOTSUP);
4441 	err = (*(vp)->v_op->vop_reqzcbuf)(vp, ioflag, uiop, cr, ct);
4442 	VOPSTATS_UPDATE(vp, reqzcbuf);
4443 	return (err);
4444 }
4445 
4446 int
4447 fop_retzcbuf(vnode_t *vp, xuio_t *uiop, cred_t *cr, caller_context_t *ct)
4448 {
4449 	int err;
4450 
4451 	if (vfs_has_feature(vp->v_vfsp, VFSFT_ZEROCOPY_SUPPORTED) == 0)
4452 		return (ENOTSUP);
4453 	err = (*(vp)->v_op->vop_retzcbuf)(vp, uiop, cr, ct);
4454 	VOPSTATS_UPDATE(vp, retzcbuf);
4455 	return (err);
4456 }
4457 
4458 /*
4459  * Default destructor
4460  *	Needed because NULL destructor means that the key is unused
4461  */
4462 /* ARGSUSED */
4463 void
4464 vsd_defaultdestructor(void *value)
4465 {}
4466 
4467 /*
4468  * Create a key (index into per vnode array)
4469  *	Locks out vsd_create, vsd_destroy, and vsd_free
4470  *	May allocate memory with lock held
4471  */
4472 void
4473 vsd_create(uint_t *keyp, void (*destructor)(void *))
4474 {
4475 	int	i;
4476 	uint_t	nkeys;
4477 
4478 	/*
4479 	 * if key is allocated, do nothing
4480 	 */
4481 	mutex_enter(&vsd_lock);
4482 	if (*keyp) {
4483 		mutex_exit(&vsd_lock);
4484 		return;
4485 	}
4486 	/*
4487 	 * find an unused key
4488 	 */
4489 	if (destructor == NULL)
4490 		destructor = vsd_defaultdestructor;
4491 
4492 	for (i = 0; i < vsd_nkeys; ++i)
4493 		if (vsd_destructor[i] == NULL)
4494 			break;
4495 
4496 	/*
4497 	 * if no unused keys, increase the size of the destructor array
4498 	 */
4499 	if (i == vsd_nkeys) {
4500 		if ((nkeys = (vsd_nkeys << 1)) == 0)
4501 			nkeys = 1;
4502 		vsd_destructor =
4503 		    (void (**)(void *))vsd_realloc((void *)vsd_destructor,
4504 		    (size_t)(vsd_nkeys * sizeof (void (*)(void *))),
4505 		    (size_t)(nkeys * sizeof (void (*)(void *))));
4506 		vsd_nkeys = nkeys;
4507 	}
4508 
4509 	/*
4510 	 * allocate the next available unused key
4511 	 */
4512 	vsd_destructor[i] = destructor;
4513 	*keyp = i + 1;
4514 
4515 	/* create vsd_list, if it doesn't exist */
4516 	if (vsd_list == NULL) {
4517 		vsd_list = kmem_alloc(sizeof (list_t), KM_SLEEP);
4518 		list_create(vsd_list, sizeof (struct vsd_node),
4519 		    offsetof(struct vsd_node, vs_nodes));
4520 	}
4521 
4522 	mutex_exit(&vsd_lock);
4523 }
4524 
4525 /*
4526  * Destroy a key
4527  *
4528  * Assumes that the caller is preventing vsd_set and vsd_get
4529  * Locks out vsd_create, vsd_destroy, and vsd_free
4530  * May free memory with lock held
4531  */
4532 void
4533 vsd_destroy(uint_t *keyp)
4534 {
4535 	uint_t key;
4536 	struct vsd_node *vsd;
4537 
4538 	/*
4539 	 * protect the key namespace and our destructor lists
4540 	 */
4541 	mutex_enter(&vsd_lock);
4542 	key = *keyp;
4543 	*keyp = 0;
4544 
4545 	ASSERT(key <= vsd_nkeys);
4546 
4547 	/*
4548 	 * if the key is valid
4549 	 */
4550 	if (key != 0) {
4551 		uint_t k = key - 1;
4552 		/*
4553 		 * for every vnode with VSD, call key's destructor
4554 		 */
4555 		for (vsd = list_head(vsd_list); vsd != NULL;
4556 		    vsd = list_next(vsd_list, vsd)) {
4557 			/*
4558 			 * no VSD for key in this vnode
4559 			 */
4560 			if (key > vsd->vs_nkeys)
4561 				continue;
4562 			/*
4563 			 * call destructor for key
4564 			 */
4565 			if (vsd->vs_value[k] && vsd_destructor[k])
4566 				(*vsd_destructor[k])(vsd->vs_value[k]);
4567 			/*
4568 			 * reset value for key
4569 			 */
4570 			vsd->vs_value[k] = NULL;
4571 		}
4572 		/*
4573 		 * actually free the key (NULL destructor == unused)
4574 		 */
4575 		vsd_destructor[k] = NULL;
4576 	}
4577 
4578 	mutex_exit(&vsd_lock);
4579 }
4580 
4581 /*
4582  * Quickly return the per vnode value that was stored with the specified key
4583  * Assumes the caller is protecting key from vsd_create and vsd_destroy
4584  * Assumes the caller is holding v_vsd_lock to protect the vsd.
4585  */
4586 void *
4587 vsd_get(vnode_t *vp, uint_t key)
4588 {
4589 	struct vsd_node *vsd;
4590 
4591 	ASSERT(vp != NULL);
4592 	ASSERT(mutex_owned(&vp->v_vsd_lock));
4593 
4594 	vsd = vp->v_vsd;
4595 
4596 	if (key && vsd != NULL && key <= vsd->vs_nkeys)
4597 		return (vsd->vs_value[key - 1]);
4598 	return (NULL);
4599 }
4600 
4601 /*
4602  * Set a per vnode value indexed with the specified key
4603  * Assumes the caller is holding v_vsd_lock to protect the vsd.
4604  */
4605 int
4606 vsd_set(vnode_t *vp, uint_t key, void *value)
4607 {
4608 	struct vsd_node *vsd;
4609 
4610 	ASSERT(vp != NULL);
4611 	ASSERT(mutex_owned(&vp->v_vsd_lock));
4612 
4613 	if (key == 0)
4614 		return (EINVAL);
4615 
4616 	vsd = vp->v_vsd;
4617 	if (vsd == NULL)
4618 		vsd = vp->v_vsd = kmem_zalloc(sizeof (*vsd), KM_SLEEP);
4619 
4620 	/*
4621 	 * If the vsd was just allocated, vs_nkeys will be 0, so the following
4622 	 * code won't happen and we will continue down and allocate space for
4623 	 * the vs_value array.
4624 	 * If the caller is replacing one value with another, then it is up
4625 	 * to the caller to free/rele/destroy the previous value (if needed).
4626 	 */
4627 	if (key <= vsd->vs_nkeys) {
4628 		vsd->vs_value[key - 1] = value;
4629 		return (0);
4630 	}
4631 
4632 	ASSERT(key <= vsd_nkeys);
4633 
4634 	if (vsd->vs_nkeys == 0) {
4635 		mutex_enter(&vsd_lock);	/* lock out vsd_destroy() */
4636 		/*
4637 		 * Link onto list of all VSD nodes.
4638 		 */
4639 		list_insert_head(vsd_list, vsd);
4640 		mutex_exit(&vsd_lock);
4641 	}
4642 
4643 	/*
4644 	 * Allocate vnode local storage and set the value for key
4645 	 */
4646 	vsd->vs_value = vsd_realloc(vsd->vs_value,
4647 	    vsd->vs_nkeys * sizeof (void *),
4648 	    key * sizeof (void *));
4649 	vsd->vs_nkeys = key;
4650 	vsd->vs_value[key - 1] = value;
4651 
4652 	return (0);
4653 }
4654 
4655 /*
4656  * Called from vn_free() to run the destructor function for each vsd
4657  *	Locks out vsd_create and vsd_destroy
4658  *	Assumes that the destructor *DOES NOT* use vsd
4659  */
4660 void
4661 vsd_free(vnode_t *vp)
4662 {
4663 	int i;
4664 	struct vsd_node *vsd = vp->v_vsd;
4665 
4666 	if (vsd == NULL)
4667 		return;
4668 
4669 	if (vsd->vs_nkeys == 0) {
4670 		kmem_free(vsd, sizeof (*vsd));
4671 		vp->v_vsd = NULL;
4672 		return;
4673 	}
4674 
4675 	/*
4676 	 * lock out vsd_create and vsd_destroy, call
4677 	 * the destructor, and mark the value as destroyed.
4678 	 */
4679 	mutex_enter(&vsd_lock);
4680 
4681 	for (i = 0; i < vsd->vs_nkeys; i++) {
4682 		if (vsd->vs_value[i] && vsd_destructor[i])
4683 			(*vsd_destructor[i])(vsd->vs_value[i]);
4684 		vsd->vs_value[i] = NULL;
4685 	}
4686 
4687 	/*
4688 	 * remove from linked list of VSD nodes
4689 	 */
4690 	list_remove(vsd_list, vsd);
4691 
4692 	mutex_exit(&vsd_lock);
4693 
4694 	/*
4695 	 * free up the VSD
4696 	 */
4697 	kmem_free(vsd->vs_value, vsd->vs_nkeys * sizeof (void *));
4698 	kmem_free(vsd, sizeof (struct vsd_node));
4699 	vp->v_vsd = NULL;
4700 }
4701 
4702 /*
4703  * realloc
4704  */
4705 static void *
4706 vsd_realloc(void *old, size_t osize, size_t nsize)
4707 {
4708 	void *new;
4709 
4710 	new = kmem_zalloc(nsize, KM_SLEEP);
4711 	if (old) {
4712 		bcopy(old, new, osize);
4713 		kmem_free(old, osize);
4714 	}
4715 	return (new);
4716 }
4717 
4718 /*
4719  * Setup the extensible system attribute for creating a reparse point.
4720  * The symlink data 'target' is validated for proper format of a reparse
4721  * string and a check also made to make sure the symlink data does not
4722  * point to an existing file.
4723  *
4724  * return 0 if ok else -1.
4725  */
4726 static int
4727 fs_reparse_mark(char *target, vattr_t *vap, xvattr_t *xvattr)
4728 {
4729 	xoptattr_t *xoap;
4730 
4731 	if ((!target) || (!vap) || (!xvattr))
4732 		return (-1);
4733 
4734 	/* validate reparse string */
4735 	if (reparse_validate((const char *)target))
4736 		return (-1);
4737 
4738 	xva_init(xvattr);
4739 	xvattr->xva_vattr = *vap;
4740 	xvattr->xva_vattr.va_mask |= AT_XVATTR;
4741 	xoap = xva_getxoptattr(xvattr);
4742 	ASSERT(xoap);
4743 	XVA_SET_REQ(xvattr, XAT_REPARSE);
4744 	xoap->xoa_reparse = 1;
4745 
4746 	return (0);
4747 }
4748 
4749 /*
4750  * Function to check whether a symlink is a reparse point.
4751  * Return B_TRUE if it is a reparse point, else return B_FALSE
4752  */
4753 boolean_t
4754 vn_is_reparse(vnode_t *vp, cred_t *cr, caller_context_t *ct)
4755 {
4756 	xvattr_t xvattr;
4757 	xoptattr_t *xoap;
4758 
4759 	if ((vp->v_type != VLNK) ||
4760 	    !(vfs_has_feature(vp->v_vfsp, VFSFT_XVATTR)))
4761 		return (B_FALSE);
4762 
4763 	xva_init(&xvattr);
4764 	xoap = xva_getxoptattr(&xvattr);
4765 	ASSERT(xoap);
4766 	XVA_SET_REQ(&xvattr, XAT_REPARSE);
4767 
4768 	if (VOP_GETATTR(vp, &xvattr.xva_vattr, 0, cr, ct))
4769 		return (B_FALSE);
4770 
4771 	if ((!(xvattr.xva_vattr.va_mask & AT_XVATTR)) ||
4772 	    (!(XVA_ISSET_RTN(&xvattr, XAT_REPARSE))))
4773 		return (B_FALSE);
4774 
4775 	return (xoap->xoa_reparse ? B_TRUE : B_FALSE);
4776 }
4777