xref: /titanic_50/usr/src/uts/common/sys/vfs.h (revision f48205be61a214698b763ff550ab9e657525104c)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
27 /*	  All Rights Reserved  	*/
28 
29 /*
30  * Portions of this source code were derived from Berkeley 4.3 BSD
31  * under license from the Regents of the University of California.
32  */
33 
34 #ifndef _SYS_VFS_H
35 #define	_SYS_VFS_H
36 
37 #pragma ident	"%Z%%M%	%I%	%E% SMI"
38 
39 #include <sys/types.h>
40 #include <sys/t_lock.h>
41 #include <sys/cred.h>
42 #include <sys/vnode.h>
43 #include <sys/statvfs.h>
44 #include <sys/refstr.h>
45 #include <sys/avl.h>
46 
47 #ifdef	__cplusplus
48 extern "C" {
49 #endif
50 
51 /*
52  * Data associated with mounted file systems.
53  */
54 
55 /*
56  * Operations vector.  This is used internal to the kernel; file systems
57  * supply their list of operations via vfs_setfsops().
58  */
59 
60 typedef struct vfsops vfsops_t;
61 
62 /*
63  * File system identifier. Should be unique (at least per machine).
64  */
65 typedef struct {
66 	int val[2];			/* file system id type */
67 } fsid_t;
68 
69 /*
70  * File identifier.  Should be unique per filesystem on a single
71  * machine.  This is typically called by a stateless file server
72  * in order to generate "file handles".
73  *
74  * Do not change the definition of struct fid ... fid_t without
75  * letting the CacheFS group know about it!  They will have to do at
76  * least two things, in the same change that changes this structure:
77  *   1. change CFSVERSION in usr/src/uts/common/sys/fs/cachefs_fs.h
78  *   2. put the old version # in the canupgrade array
79  *	in cachfs_upgrade() in usr/src/cmd/fs.d/cachefs/fsck/fsck.c
80  * This is necessary because CacheFS stores FIDs on disk.
81  *
82  * Many underlying file systems cast a struct fid into other
83  * file system dependent structures which may require 4 byte alignment.
84  * Because a fid starts with a short it may not be 4 byte aligned, the
85  * fid_pad will force the alignment.
86  */
87 #define	MAXFIDSZ	64
88 #define	OLD_MAXFIDSZ	16
89 
90 typedef struct fid {
91 	union {
92 		long fid_pad;
93 		struct {
94 			ushort_t len;	/* length of data in bytes */
95 			char	data[MAXFIDSZ]; /* data (variable len) */
96 		} _fid;
97 	} un;
98 } fid_t;
99 
100 #ifdef _SYSCALL32
101 /*
102  * Solaris 64 - use old-style cache format with 32-bit aligned fid for on-disk
103  * struct compatibility.
104  */
105 typedef struct fid32 {
106 	union {
107 		int32_t fid_pad;
108 		struct {
109 			uint16_t  len;   /* length of data in bytes */
110 			char    data[MAXFIDSZ]; /* data (variable len) */
111 		} _fid;
112 	} un;
113 } fid32_t;
114 #else /* not _SYSCALL32 */
115 #define	fid32	fid
116 typedef fid_t	fid32_t;
117 #endif /* _SYSCALL32 */
118 
119 #define	fid_len		un._fid.len
120 #define	fid_data	un._fid.data
121 
122 /*
123  * Structure defining a mount option for a filesystem.
124  * option names are found in mntent.h
125  */
126 typedef struct mntopt {
127 	char	*mo_name;	/* option name */
128 	char	**mo_cancel;	/* list of options cancelled by this one */
129 	char	*mo_arg;	/* argument string for this option */
130 	int	mo_flags;	/* flags for this mount option */
131 	void	*mo_data;	/* filesystem specific data */
132 } mntopt_t;
133 
134 /*
135  * Flags that apply to mount options
136  */
137 
138 #define	MO_SET		0x01		/* option is set */
139 #define	MO_NODISPLAY	0x02		/* option not listed in mnttab */
140 #define	MO_HASVALUE	0x04		/* option takes a value */
141 #define	MO_IGNORE	0x08		/* option ignored by parser */
142 #define	MO_DEFAULT	MO_SET		/* option is on by default */
143 #define	MO_TAG		0x10		/* flags a tag set by user program */
144 #define	MO_EMPTY	0x20		/* empty space in option table */
145 
146 #define	VFS_NOFORCEOPT	0x01		/* honor MO_IGNORE (don't set option) */
147 #define	VFS_DISPLAY	0x02		/* Turn off MO_NODISPLAY bit for opt */
148 #define	VFS_NODISPLAY	0x04		/* Turn on MO_NODISPLAY bit for opt */
149 #define	VFS_CREATEOPT	0x08		/* Create the opt if it's not there */
150 
151 /*
152  * Structure holding mount option strings for the mounted file system.
153  */
154 typedef struct mntopts {
155 	uint_t		mo_count;		/* number of entries in table */
156 	mntopt_t	*mo_list;		/* list of mount options */
157 } mntopts_t;
158 
159 /*
160  * The kstat structures associated with the vopstats are kept in an
161  * AVL tree.  This is to avoid the case where a file system does not
162  * use a unique fsid_t for each vfs (e.g., namefs).  In order to do
163  * this, we need a structure that the AVL tree can use that also
164  * references the kstat.
165  * Note that the vks_fsid is generated from the value reported by
166  * VFS_STATVFS().
167  */
168 typedef struct vskstat_anchor {
169 	avl_node_t	vsk_node;	/* Required for use by AVL routines */
170 	kstat_t		*vsk_ksp;	/* kstat structure for vopstats */
171 	ulong_t		vsk_fsid;	/* fsid associated w/this FS */
172 } vsk_anchor_t;
173 
174 extern avl_tree_t	vskstat_tree;
175 extern kmutex_t		vskstat_tree_lock;
176 
177 /*
178  * Structure per mounted file system.  Each mounted file system has
179  * an array of operations and an instance record.
180  *
181  * The file systems are kept on a doubly linked circular list headed by
182  * "rootvfs".
183  * File system implementations should not access this list;
184  * it's intended for use only in the kernel's vfs layer.
185  *
186  * Each zone also has its own list of mounts, containing filesystems mounted
187  * somewhere within the filesystem tree rooted at the zone's rootpath.  The
188  * list is doubly linked to match the global list.
189  *
190  * mnttab locking: the in-kernel mnttab uses the vfs_mntpt, vfs_resource and
191  * vfs_mntopts fields in the vfs_t. mntpt and resource are refstr_ts that
192  * are set at mount time and can only be modified during a remount.
193  * It is safe to read these fields if you can prevent a remount on the vfs,
194  * or through the convenience funcs vfs_getmntpoint() and vfs_getresource().
195  * The mntopts field may only be accessed through the provided convenience
196  * functions, as it is protected by the vfs list lock. Modifying a mount
197  * option requires grabbing the vfs list write lock, which can be a very
198  * high latency lock.
199  */
200 struct zone;		/* from zone.h */
201 struct fem_head;	/* from fem.h */
202 
203 /*
204  * Private vfs data, NOT to be used by a file system implementation.
205  */
206 typedef struct vfs_impl {
207 	struct fem_head	*vi_femhead;		/* fs monitoring */
208 	/*
209 	 * Support for statistics on the vnode operations
210 	 */
211 	vsk_anchor_t	*vi_vskap;		/* anchor for vopstats' kstat */
212 	vopstats_t	*vi_fstypevsp;		/* ptr to per-fstype vopstats */
213 	vopstats_t	vi_vopstats;		/* per-mount vnode op stats */
214 } vfs_impl_t;
215 
216 typedef struct vfs {
217 	struct vfs	*vfs_next;		/* next VFS in VFS list */
218 	struct vfs	*vfs_prev;		/* prev VFS in VFS list */
219 
220 /* vfs_op should not be used directly.  Accessor functions are provided */
221 	vfsops_t	*vfs_op;		/* operations on VFS */
222 
223 	struct vnode	*vfs_vnodecovered;	/* vnode mounted on */
224 	uint_t		vfs_flag;		/* flags */
225 	uint_t		vfs_bsize;		/* native block size */
226 	int		vfs_fstype;		/* file system type index */
227 	fsid_t		vfs_fsid;		/* file system id */
228 	void		*vfs_data;		/* private data */
229 	dev_t		vfs_dev;		/* device of mounted VFS */
230 	ulong_t		vfs_bcount;		/* I/O count (accounting) */
231 	struct vfs	*vfs_list;		/* sync list pointer */
232 	struct vfs	*vfs_hash;		/* hash list pointer */
233 	ksema_t		vfs_reflock;		/* mount/unmount/sync lock */
234 	uint_t		vfs_count;		/* vfs reference count */
235 	mntopts_t	vfs_mntopts;		/* options mounted with */
236 	refstr_t	*vfs_resource;		/* mounted resource name */
237 	refstr_t	*vfs_mntpt;		/* mount point name */
238 	time_t		vfs_mtime;		/* time we were mounted */
239 	vfs_impl_t 	*vfs_implp;		/* impl specific data */
240 	/*
241 	 * Zones support.  Note that the zone that "owns" the mount isn't
242 	 * necessarily the same as the zone in which the zone is visible.
243 	 * That is, vfs_zone and (vfs_zone_next|vfs_zone_prev) may refer to
244 	 * different zones.
245 	 */
246 	struct zone	*vfs_zone;		/* zone that owns the mount */
247 	struct vfs	*vfs_zone_next;		/* next VFS visible in zone */
248 	struct vfs	*vfs_zone_prev;		/* prev VFS visible in zone */
249 } vfs_t;
250 
251 #define	vfs_femhead	vfs_implp->vi_femhead
252 #define	vfs_vskap	vfs_implp->vi_vskap
253 #define	vfs_fstypevsp	vfs_implp->vi_fstypevsp
254 #define	vfs_vopstats	vfs_implp->vi_vopstats
255 
256 /*
257  * VFS flags.
258  */
259 #define	VFS_RDONLY	0x01		/* read-only vfs */
260 #define	VFS_NOMNTTAB	0x02		/* vfs not seen in mnttab */
261 #define	VFS_NOSETUID	0x08		/* setuid disallowed */
262 #define	VFS_REMOUNT	0x10		/* modify mount options only */
263 #define	VFS_NOTRUNC	0x20		/* does not truncate long file names */
264 #define	VFS_UNLINKABLE	0x40		/* unlink(2) can be applied to root */
265 #define	VFS_PXFS	0x80		/* clustering: global fs proxy vfs */
266 #define	VFS_UNMOUNTED	0x100		/* file system has been unmounted */
267 #define	VFS_NBMAND	0x200		/* allow non-blocking mandatory locks */
268 #define	VFS_XATTR	0x400		/* fs supports extended attributes */
269 #define	VFS_NODEVICES	0x800		/* device-special files disallowed */
270 #define	VFS_NOEXEC	0x1000		/* executables disallowed */
271 #define	VFS_STATS	0x2000		/* file system can collect stats */
272 #define	VFS_XID		0x4000		/* file system supports extended ids */
273 
274 #define	VFS_NORESOURCE	"unspecified_resource"
275 #define	VFS_NOMNTPT	"unspecified_mountpoint"
276 
277 /*
278  * Argument structure for mount(2).
279  *
280  * Flags are defined in <sys/mount.h>.
281  *
282  * Note that if the MS_SYSSPACE bit is set in flags, the pointer fields in
283  * this structure are to be interpreted as kernel addresses.  File systems
284  * should be prepared for this possibility.
285  */
286 struct mounta {
287 	char	*spec;
288 	char	*dir;
289 	int	flags;
290 	char	*fstype;
291 	char	*dataptr;
292 	int	datalen;
293 	char	*optptr;
294 	int	optlen;
295 };
296 
297 /*
298  * Reasons for calling the vfs_mountroot() operation.
299  */
300 enum whymountroot { ROOT_INIT, ROOT_REMOUNT, ROOT_UNMOUNT};
301 typedef enum whymountroot whymountroot_t;
302 
303 /*
304  * Reasons for calling the VFS_VNSTATE():
305  */
306 enum vntrans {
307 	VNTRANS_EXISTS,
308 	VNTRANS_IDLED,
309 	VNTRANS_RECLAIMED,
310 	VNTRANS_DESTROYED
311 };
312 typedef enum vntrans vntrans_t;
313 
314 /*
315  * VFS_OPS defines all the vfs operations.  It is used to define
316  * the vfsops structure (below) and the fs_func_p union (vfs_opreg.h).
317  */
318 #define	VFS_OPS								\
319 	int	(*vfs_mount)(vfs_t *, vnode_t *, struct mounta *, cred_t *); \
320 	int	(*vfs_unmount)(vfs_t *, int, cred_t *);			\
321 	int	(*vfs_root)(vfs_t *, vnode_t **);			\
322 	int	(*vfs_statvfs)(vfs_t *, statvfs64_t *);			\
323 	int	(*vfs_sync)(vfs_t *, short, cred_t *);			\
324 	int	(*vfs_vget)(vfs_t *, vnode_t **, fid_t *);		\
325 	int	(*vfs_mountroot)(vfs_t *, enum whymountroot);		\
326 	void	(*vfs_freevfs)(vfs_t *);				\
327 	int	(*vfs_vnstate)(vfs_t *, vnode_t *, vntrans_t)	/* NB: No ";" */
328 
329 /*
330  * Operations supported on virtual file system.
331  */
332 struct vfsops {
333 	VFS_OPS;	/* Signature of all vfs operations (vfsops) */
334 };
335 
336 extern int	fsop_mount(vfs_t *, vnode_t *, struct mounta *, cred_t *);
337 extern int	fsop_unmount(vfs_t *, int, cred_t *);
338 extern int	fsop_root(vfs_t *, vnode_t **);
339 extern int	fsop_statfs(vfs_t *, statvfs64_t *);
340 extern int	fsop_sync(vfs_t *, short, cred_t *);
341 extern int	fsop_vget(vfs_t *, vnode_t **, fid_t *);
342 extern int	fsop_mountroot(vfs_t *, enum whymountroot);
343 extern void	fsop_freefs(vfs_t *);
344 extern int	fsop_sync_by_kind(int, short, cred_t *);
345 extern int	fsop_vnstate(vfs_t *, vnode_t *, vntrans_t);
346 
347 #define	VFS_MOUNT(vfsp, mvp, uap, cr) fsop_mount(vfsp, mvp, uap, cr)
348 #define	VFS_UNMOUNT(vfsp, flag, cr) fsop_unmount(vfsp, flag, cr)
349 #define	VFS_ROOT(vfsp, vpp) fsop_root(vfsp, vpp)
350 #define	VFS_STATVFS(vfsp, sp) fsop_statfs(vfsp, sp)
351 #define	VFS_SYNC(vfsp, flag, cr) fsop_sync(vfsp, flag, cr)
352 #define	VFS_VGET(vfsp, vpp, fidp) fsop_vget(vfsp, vpp, fidp)
353 #define	VFS_MOUNTROOT(vfsp, init) fsop_mountroot(vfsp, init)
354 #define	VFS_FREEVFS(vfsp) fsop_freefs(vfsp)
355 #define	VFS_VNSTATE(vfsp, vn, ns)	fsop_vnstate(vfsp, vn, ns)
356 
357 #define	VFSNAME_MOUNT		"mount"
358 #define	VFSNAME_UNMOUNT		"unmount"
359 #define	VFSNAME_ROOT		"root"
360 #define	VFSNAME_STATVFS		"statvfs"
361 #define	VFSNAME_SYNC		"sync"
362 #define	VFSNAME_VGET		"vget"
363 #define	VFSNAME_MOUNTROOT	"mountroot"
364 #define	VFSNAME_FREEVFS		"freevfs"
365 #define	VFSNAME_VNSTATE		"vnstate"
366 /*
367  * Filesystem type switch table.
368  */
369 
370 typedef struct vfssw {
371 	char		*vsw_name;	/* type name -- max len _ST_FSTYPSZ */
372 	int		(*vsw_init) (int, char *);
373 				/* init routine (for non-loadable fs only) */
374 	int		vsw_flag;	/* flags */
375 	mntopts_t	vsw_optproto;	/* mount options table prototype */
376 	uint_t		vsw_count;	/* count of references */
377 	kmutex_t	vsw_lock;	/* lock to protect vsw_count */
378 	vfsops_t	vsw_vfsops;	/* filesystem operations vector */
379 } vfssw_t;
380 
381 /*
382  * Filesystem type definition record.  All file systems must export a record
383  * of this type through their modlfs structure.
384  */
385 
386 typedef struct vfsdef_v3 {
387 	int		def_version;	/* structure version, must be first */
388 	char		*name;		/* filesystem type name */
389 	int		(*init) (int, char *);	/* init routine */
390 	int		flags;		/* filesystem flags */
391 	mntopts_t	*optproto;	/* mount options table prototype */
392 } vfsdef_v3;
393 
394 typedef struct vfsdef_v3 vfsdef_t;
395 
396 enum {
397 	VFSDEF_VERSION = 3
398 };
399 
400 /*
401  * flags for vfssw and vfsdef
402  */
403 #define	VSW_HASPROTO	0x01	/* struct has a mount options prototype */
404 #define	VSW_CANRWRO	0x02	/* file system can transition from rw to ro */
405 #define	VSW_CANREMOUNT	0x04	/* file system supports remounts */
406 #define	VSW_NOTZONESAFE	0x08	/* zone_enter(2) should fail for these files */
407 #define	VSW_VOLATILEDEV	0x10	/* vfs_dev can change each time fs is mounted */
408 #define	VSW_STATS	0x20	/* file system can collect stats */
409 #define	VSW_XID		0x40	/* file system supports extended ids */
410 
411 #define	VSW_INSTALLED	0x8000	/* this vsw is associated with a file system */
412 
413 #if defined(_KERNEL)
414 /*
415  * Public operations.
416  */
417 struct umounta;
418 struct statvfsa;
419 struct fstatvfsa;
420 
421 void	vfs_freevfsops(vfsops_t *);
422 int	vfs_freevfsops_by_type(int);
423 void	vfs_setops(vfs_t *, vfsops_t *);
424 vfsops_t *vfs_getops(vfs_t *vfsp);
425 int	vfs_matchops(vfs_t *, vfsops_t *);
426 int	vfs_can_sync(vfs_t *vfsp);
427 void	vfs_init(vfs_t *vfsp, vfsops_t *, void *);
428 void	vfsimpl_setup(vfs_t *vfsp);
429 void	vfsimpl_teardown(vfs_t *vfsp);
430 void	vn_exists(vnode_t *);
431 void	vn_idle(vnode_t *);
432 void	vn_reclaim(vnode_t *);
433 void	vn_invalid(vnode_t *);
434 
435 int	rootconf(void);
436 int	svm_rootconf(void);
437 int	domount(char *, struct mounta *, vnode_t *, struct cred *,
438 	    struct vfs **);
439 int	dounmount(struct vfs *, int, cred_t *);
440 int	vfs_lock(struct vfs *);
441 int	vfs_rlock(struct vfs *);
442 void	vfs_lock_wait(struct vfs *);
443 void	vfs_rlock_wait(struct vfs *);
444 void	vfs_unlock(struct vfs *);
445 int	vfs_lock_held(struct vfs *);
446 struct	_kthread *vfs_lock_owner(struct vfs *);
447 void	sync(void);
448 void	vfs_sync(int);
449 void	vfs_mountroot(void);
450 void	vfs_add(vnode_t *, struct vfs *, int);
451 void	vfs_remove(struct vfs *);
452 
453 /* The following functions are not for general use by filesystems */
454 
455 void	vfs_createopttbl(mntopts_t *, const char *);
456 void	vfs_copyopttbl(const mntopts_t *, mntopts_t *);
457 void	vfs_mergeopttbl(const mntopts_t *, const mntopts_t *, mntopts_t *);
458 void	vfs_freeopttbl(mntopts_t *);
459 void	vfs_parsemntopts(mntopts_t *, char *, int);
460 int	vfs_buildoptionstr(const mntopts_t *, char *, int);
461 struct mntopt *vfs_hasopt(const mntopts_t *, const char *);
462 void	vfs_mnttab_modtimeupd(void);
463 
464 void	vfs_clearmntopt(struct vfs *, const char *);
465 void	vfs_setmntopt(struct vfs *, const char *, const char *, int);
466 void	vfs_setresource(struct vfs *, const char *);
467 void	vfs_setmntpoint(struct vfs *, const char *);
468 refstr_t *vfs_getresource(const struct vfs *);
469 refstr_t *vfs_getmntpoint(const struct vfs *);
470 int	vfs_optionisset(const struct vfs *, const char *, char **);
471 int	vfs_settag(uint_t, uint_t, const char *, const char *, cred_t *);
472 int	vfs_clrtag(uint_t, uint_t, const char *, const char *, cred_t *);
473 void	vfs_syncall(void);
474 void	vfs_syncprogress(void);
475 void	vfsinit(void);
476 void	vfs_unmountall(void);
477 void	vfs_make_fsid(fsid_t *, dev_t, int);
478 void	vfs_addmip(dev_t, struct vfs *);
479 void	vfs_delmip(struct vfs *);
480 int	vfs_devismounted(dev_t);
481 int	vfs_devmounting(dev_t, struct vfs *);
482 int	vfs_opsinuse(vfsops_t *);
483 struct vfs *getvfs(fsid_t *);
484 struct vfs *vfs_dev2vfsp(dev_t);
485 struct vfs *vfs_mntpoint2vfsp(const char *);
486 struct vfssw *allocate_vfssw(char *);
487 struct vfssw *vfs_getvfssw(char *);
488 struct vfssw *vfs_getvfsswbyname(char *);
489 struct vfssw *vfs_getvfsswbyvfsops(vfsops_t *);
490 void	vfs_refvfssw(struct vfssw *);
491 void	vfs_unrefvfssw(struct vfssw *);
492 uint_t	vf_to_stf(uint_t);
493 void	vfs_mnttab_modtime(timespec_t *);
494 void	vfs_mnttab_poll(timespec_t *, struct pollhead **);
495 
496 void	vfs_list_lock(void);
497 void	vfs_list_read_lock(void);
498 void	vfs_list_unlock(void);
499 void	vfs_list_add(struct vfs *);
500 void	vfs_list_remove(struct vfs *);
501 void	vfs_hold(vfs_t *vfsp);
502 void	vfs_rele(vfs_t *vfsp);
503 void	fs_freevfs(vfs_t *);
504 void	vfs_root_redev(vfs_t *vfsp, dev_t ndev, int fstype);
505 
506 int	vfs_zone_change_safe(vfs_t *);
507 
508 #define	VFSHASH(maj, min) (((int)((maj)+(min))) & (vfshsz - 1))
509 #define	VFS_ON_LIST(vfsp) \
510 	((vfsp)->vfs_next != (vfsp) && (vfsp)->vfs_next != NULL)
511 
512 /*
513  * Globals.
514  */
515 
516 extern struct vfssw vfssw[];		/* table of filesystem types */
517 extern krwlock_t vfssw_lock;
518 extern char rootfstype[];		/* name of root fstype */
519 extern const int nfstype;		/* # of elements in vfssw array */
520 extern vfsops_t *EIO_vfsops;		/* operations for vfs being torn-down */
521 
522 /*
523  * The following variables are private to the the kernel's vfs layer.  File
524  * system implementations should not access them.
525  */
526 extern struct vfs *rootvfs;		/* ptr to root vfs structure */
527 typedef struct {
528 	struct vfs *rvfs_head;		/* head vfs in chain */
529 	kmutex_t rvfs_lock;		/* mutex protecting this chain */
530 	uint32_t rvfs_len;		/* length of this chain */
531 } rvfs_t;
532 extern rvfs_t *rvfs_list;
533 extern int vfshsz;			/* # of elements in rvfs_head array */
534 extern const mntopts_t vfs_mntopts;	/* globally recognized options */
535 
536 #endif /* defined(_KERNEL) */
537 
538 #define	VFS_HOLD(vfsp) { \
539 	vfs_hold(vfsp); \
540 }
541 
542 #define	VFS_RELE(vfsp)	{ \
543 	vfs_rele(vfsp); \
544 }
545 
546 #define	VFS_INIT(vfsp, op, data) { \
547 	vfs_init((vfsp), (op), (data)); \
548 	vfsimpl_setup((vfsp)); \
549 }
550 
551 
552 #define	VFS_INSTALLED(vfsswp)	(((vfsswp)->vsw_flag & VSW_INSTALLED) != 0)
553 #define	ALLOCATED_VFSSW(vswp)		((vswp)->vsw_name[0] != '\0')
554 #define	RLOCK_VFSSW()			(rw_enter(&vfssw_lock, RW_READER))
555 #define	RUNLOCK_VFSSW()			(rw_exit(&vfssw_lock))
556 #define	WLOCK_VFSSW()			(rw_enter(&vfssw_lock, RW_WRITER))
557 #define	WUNLOCK_VFSSW()			(rw_exit(&vfssw_lock))
558 #define	VFSSW_LOCKED()			(RW_LOCK_HELD(&vfssw_lock))
559 #define	VFSSW_WRITE_LOCKED()		(RW_WRITE_HELD(&vfssw_lock))
560 /*
561  * VFS_SYNC flags.
562  */
563 #define	SYNC_ATTR	0x01		/* sync attributes only */
564 #define	SYNC_CLOSE	0x02		/* close open file */
565 #define	SYNC_ALL	0x04		/* force to sync all fs */
566 
567 #ifdef	__cplusplus
568 }
569 #endif
570 
571 #endif	/* _SYS_VFS_H */
572