xref: /illumos-gate/usr/src/uts/common/sys/vfs.h (revision 8c69cc8fbe729fa7b091e901c4b50508ccc6bb33)
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 2016 Toomas Soome <tsoome@me.com>
25  * Copyright (c) 2016 by Delphix. All rights reserved.
26  * Copyright 2016 Nexenta Systems, Inc.
27  */
28 
29 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
30 /*	  All Rights Reserved	*/
31 
32 /*
33  * Portions of this source code were derived from Berkeley 4.3 BSD
34  * under license from the Regents of the University of California.
35  */
36 
37 #ifndef _SYS_VFS_H
38 #define	_SYS_VFS_H
39 
40 #include <sys/zone.h>
41 #include <sys/types.h>
42 #include <sys/t_lock.h>
43 #include <sys/cred.h>
44 #include <sys/vnode.h>
45 #include <sys/statvfs.h>
46 #include <sys/refstr.h>
47 #include <sys/avl.h>
48 #include <sys/time.h>
49 
50 #ifdef	__cplusplus
51 extern "C" {
52 #endif
53 
54 /*
55  * Data associated with mounted file systems.
56  */
57 
58 /*
59  * Operations vector.  This is used internal to the kernel; file systems
60  * supply their list of operations via vfs_setfsops().
61  */
62 
63 typedef struct vfsops vfsops_t;
64 
65 /*
66  * File system identifier. Should be unique (at least per machine).
67  */
68 typedef struct {
69 	int val[2];			/* file system id type */
70 } fsid_t;
71 
72 /*
73  * File identifier.  Should be unique per filesystem on a single
74  * machine.  This is typically called by a stateless file server
75  * in order to generate "file handles".
76  *
77  * Many underlying file systems cast a struct fid into other
78  * file system dependent structures which may require 4 byte alignment.
79  * Because a fid starts with a short it may not be 4 byte aligned, the
80  * fid_pad will force the alignment.
81  */
82 #define	MAXFIDSZ	64
83 #define	OLD_MAXFIDSZ	16
84 
85 typedef struct fid {
86 	union {
87 		long fid_pad;
88 		struct {
89 			ushort_t len;	/* length of data in bytes */
90 			char	data[MAXFIDSZ]; /* data (variable len) */
91 		} _fid;
92 	} un;
93 } fid_t;
94 
95 #ifdef _SYSCALL32
96 /*
97  * Solaris 64 - use old-style cache format with 32-bit aligned fid for on-disk
98  * struct compatibility.
99  */
100 typedef struct fid32 {
101 	union {
102 		int32_t fid_pad;
103 		struct {
104 			uint16_t  len;   /* length of data in bytes */
105 			char    data[MAXFIDSZ]; /* data (variable len) */
106 		} _fid;
107 	} un;
108 } fid32_t;
109 #else /* not _SYSCALL32 */
110 #define	fid32	fid
111 typedef fid_t	fid32_t;
112 #endif /* _SYSCALL32 */
113 
114 #define	fid_len		un._fid.len
115 #define	fid_data	un._fid.data
116 
117 /*
118  * Structure defining a mount option for a filesystem.
119  * option names are found in mntent.h
120  */
121 typedef struct mntopt {
122 	char	*mo_name;	/* option name */
123 	char	**mo_cancel;	/* list of options cancelled by this one */
124 	char	*mo_arg;	/* argument string for this option */
125 	int	mo_flags;	/* flags for this mount option */
126 	void	*mo_data;	/* filesystem specific data */
127 } mntopt_t;
128 
129 /*
130  * Flags that apply to mount options
131  */
132 
133 #define	MO_SET		0x01		/* option is set */
134 #define	MO_NODISPLAY	0x02		/* option not listed in mnttab */
135 #define	MO_HASVALUE	0x04		/* option takes a value */
136 #define	MO_IGNORE	0x08		/* option ignored by parser */
137 #define	MO_DEFAULT	MO_SET		/* option is on by default */
138 #define	MO_TAG		0x10		/* flags a tag set by user program */
139 #define	MO_EMPTY	0x20		/* empty space in option table */
140 
141 #define	VFS_NOFORCEOPT	0x01		/* honor MO_IGNORE (don't set option) */
142 #define	VFS_DISPLAY	0x02		/* Turn off MO_NODISPLAY bit for opt */
143 #define	VFS_NODISPLAY	0x04		/* Turn on MO_NODISPLAY bit for opt */
144 #define	VFS_CREATEOPT	0x08		/* Create the opt if it's not there */
145 
146 /*
147  * Structure holding mount option strings for the mounted file system.
148  */
149 typedef struct mntopts {
150 	uint_t		mo_count;		/* number of entries in table */
151 	mntopt_t	*mo_list;		/* list of mount options */
152 } mntopts_t;
153 
154 /*
155  * The kstat structures associated with the vopstats are kept in an
156  * AVL tree.  This is to avoid the case where a file system does not
157  * use a unique fsid_t for each vfs (e.g., namefs).  In order to do
158  * this, we need a structure that the AVL tree can use that also
159  * references the kstat.
160  * Note that the vks_fsid is generated from the value reported by
161  * VFS_STATVFS().
162  */
163 typedef struct vskstat_anchor {
164 	avl_node_t	vsk_node;	/* Required for use by AVL routines */
165 	kstat_t		*vsk_ksp;	/* kstat structure for vopstats */
166 	ulong_t		vsk_fsid;	/* fsid associated w/this FS */
167 } vsk_anchor_t;
168 
169 extern avl_tree_t	vskstat_tree;
170 extern kmutex_t		vskstat_tree_lock;
171 
172 /*
173  * Structure per mounted file system.  Each mounted file system has
174  * an array of operations and an instance record.
175  *
176  * The file systems are kept on a doubly linked circular list headed by
177  * "rootvfs".
178  * File system implementations should not access this list;
179  * it's intended for use only in the kernel's vfs layer.
180  *
181  * Each zone also has its own list of mounts, containing filesystems mounted
182  * somewhere within the filesystem tree rooted at the zone's rootpath.  The
183  * list is doubly linked to match the global list.
184  *
185  * mnttab locking: the in-kernel mnttab uses the vfs_mntpt, vfs_resource and
186  * vfs_mntopts fields in the vfs_t. mntpt and resource are refstr_ts that
187  * are set at mount time and can only be modified during a remount.
188  * It is safe to read these fields if you can prevent a remount on the vfs,
189  * or through the convenience funcs vfs_getmntpoint() and vfs_getresource().
190  * The mntopts field may only be accessed through the provided convenience
191  * functions, as it is protected by the vfs list lock. Modifying a mount
192  * option requires grabbing the vfs list write lock, which can be a very
193  * high latency lock.
194  */
195 struct zone;		/* from zone.h */
196 struct fem_head;	/* from fem.h */
197 
198 typedef struct vfs {
199 	struct vfs	*vfs_next;		/* next VFS in VFS list */
200 	struct vfs	*vfs_prev;		/* prev VFS in VFS list */
201 
202 /* vfs_op should not be used directly.  Accessor functions are provided */
203 	vfsops_t	*vfs_op;		/* operations on VFS */
204 
205 	struct vnode	*vfs_vnodecovered;	/* vnode mounted on */
206 	uint_t		vfs_flag;		/* flags */
207 	uint_t		vfs_bsize;		/* native block size */
208 	int		vfs_fstype;		/* file system type index */
209 	fsid_t		vfs_fsid;		/* file system id */
210 	void		*vfs_data;		/* private data */
211 	dev_t		vfs_dev;		/* device of mounted VFS */
212 	ulong_t		vfs_bcount;		/* I/O count (accounting) */
213 	struct vfs	*vfs_list;		/* sync list pointer */
214 	struct vfs	*vfs_hash;		/* hash list pointer */
215 	ksema_t		vfs_reflock;		/* mount/unmount/sync lock */
216 	uint_t		vfs_count;		/* vfs reference count */
217 	mntopts_t	vfs_mntopts;		/* options mounted with */
218 	refstr_t	*vfs_resource;		/* mounted resource name */
219 	refstr_t	*vfs_mntpt;		/* mount point name */
220 	time_t		vfs_mtime;		/* time we were mounted */
221 	struct vfs_impl	*vfs_implp;		/* impl specific data */
222 	/*
223 	 * Zones support.  Note that the zone that "owns" the mount isn't
224 	 * necessarily the same as the zone in which the zone is visible.
225 	 * That is, vfs_zone and (vfs_zone_next|vfs_zone_prev) may refer to
226 	 * different zones.
227 	 */
228 	struct zone	*vfs_zone;		/* zone that owns the mount */
229 	struct vfs	*vfs_zone_next;		/* next VFS visible in zone */
230 	struct vfs	*vfs_zone_prev;		/* prev VFS visible in zone */
231 
232 	struct fem_head	*vfs_femhead;		/* fs monitoring */
233 	uint32_t	vfs_lofi_id;		/* ID if lofi mount */
234 } vfs_t;
235 
236 #define	vfs_featureset	vfs_implp->vi_featureset
237 #define	vfs_vskap	vfs_implp->vi_vskap
238 #define	vfs_fstypevsp	vfs_implp->vi_fstypevsp
239 #define	vfs_vopstats	vfs_implp->vi_vopstats
240 #define	vfs_hrctime	vfs_implp->vi_hrctime
241 
242 /*
243  * VFS flags.
244  */
245 #define	VFS_RDONLY	0x01		/* read-only vfs */
246 #define	VFS_NOMNTTAB	0x02		/* vfs not seen in mnttab */
247 #define	VFS_NOSETUID	0x08		/* setuid disallowed */
248 #define	VFS_REMOUNT	0x10		/* modify mount options only */
249 #define	VFS_NOTRUNC	0x20		/* does not truncate long file names */
250 #define	VFS_UNLINKABLE	0x40		/* unlink(2) can be applied to root */
251 #define	VFS_PXFS	0x80		/* clustering: global fs proxy vfs */
252 #define	VFS_UNMOUNTED	0x100		/* file system has been unmounted */
253 #define	VFS_NBMAND	0x200		/* allow non-blocking mandatory locks */
254 #define	VFS_XATTR	0x400		/* fs supports extended attributes */
255 #define	VFS_NODEVICES	0x800		/* device-special files disallowed */
256 #define	VFS_NOEXEC	0x1000		/* executables disallowed */
257 #define	VFS_STATS	0x2000		/* file system can collect stats */
258 #define	VFS_XID		0x4000		/* file system supports extended ids */
259 
260 #define	VFS_NORESOURCE	"unspecified_resource"
261 #define	VFS_NOMNTPT	"unspecified_mountpoint"
262 
263 /*
264  * VFS features are implemented as bits set in the vfs_t.
265  * The vfs_feature_t typedef is a 64-bit number that will translate
266  * into an element in an array of bitmaps and a bit in that element.
267  * Developers must not depend on the implementation of this and
268  * need to use vfs_has_feature()/vfs_set_feature() routines.
269  */
270 typedef	uint64_t	vfs_feature_t;
271 
272 #define	VFSFT_XVATTR		0x100000001	/* Supports xvattr for attrs */
273 #define	VFSFT_CASEINSENSITIVE	0x100000002	/* Supports case-insensitive */
274 #define	VFSFT_NOCASESENSITIVE	0x100000004	/* NOT case-sensitive */
275 #define	VFSFT_DIRENTFLAGS	0x100000008	/* Supports dirent flags */
276 #define	VFSFT_ACLONCREATE	0x100000010	/* Supports ACL on create */
277 #define	VFSFT_ACEMASKONACCESS	0x100000020	/* Can use ACEMASK for access */
278 #define	VFSFT_SYSATTR_VIEWS	0x100000040	/* Supports sysattr view i/f */
279 #define	VFSFT_ACCESS_FILTER	0x100000080	/* dirents filtered by access */
280 #define	VFSFT_REPARSE		0x100000100	/* Supports reparse point */
281 #define	VFSFT_ZEROCOPY_SUPPORTED	0x100000200
282 				/* Support loaning /returning cache buffer */
283 /*
284  * Argument structure for mount(2).
285  *
286  * Flags are defined in <sys/mount.h>.
287  *
288  * Note that if the MS_SYSSPACE bit is set in flags, the pointer fields in
289  * this structure are to be interpreted as kernel addresses.  File systems
290  * should be prepared for this possibility.
291  */
292 struct mounta {
293 	char	*spec;
294 	char	*dir;
295 	int	flags;
296 	char	*fstype;
297 	char	*dataptr;
298 	int	datalen;
299 	char	*optptr;
300 	int	optlen;
301 };
302 
303 /*
304  * Reasons for calling the vfs_mountroot() operation.
305  */
306 enum whymountroot { ROOT_INIT, ROOT_REMOUNT, ROOT_UNMOUNT};
307 typedef enum whymountroot whymountroot_t;
308 
309 /*
310  * Reasons for calling the VFS_VNSTATE():
311  */
312 enum vntrans {
313 	VNTRANS_EXISTS,
314 	VNTRANS_IDLED,
315 	VNTRANS_RECLAIMED,
316 	VNTRANS_DESTROYED
317 };
318 typedef enum vntrans vntrans_t;
319 
320 /*
321  * VFS_OPS defines all the vfs operations.  It is used to define
322  * the vfsops structure (below) and the fs_func_p union (vfs_opreg.h).
323  */
324 #define	VFS_OPS								\
325 	int	(*vfs_mount)(vfs_t *, vnode_t *, struct mounta *, cred_t *); \
326 	int	(*vfs_unmount)(vfs_t *, int, cred_t *);			\
327 	int	(*vfs_root)(vfs_t *, vnode_t **);			\
328 	int	(*vfs_statvfs)(vfs_t *, statvfs64_t *);			\
329 	int	(*vfs_sync)(vfs_t *, short, cred_t *);			\
330 	int	(*vfs_vget)(vfs_t *, vnode_t **, fid_t *);		\
331 	int	(*vfs_mountroot)(vfs_t *, enum whymountroot);		\
332 	void	(*vfs_freevfs)(vfs_t *);				\
333 	int	(*vfs_vnstate)(vfs_t *, vnode_t *, vntrans_t)	/* NB: No ";" */
334 
335 /*
336  * Operations supported on virtual file system.
337  */
338 struct vfsops {
339 	VFS_OPS;	/* Signature of all vfs operations (vfsops) */
340 };
341 
342 extern int	fsop_mount(vfs_t *, vnode_t *, struct mounta *, cred_t *);
343 extern int	fsop_unmount(vfs_t *, int, cred_t *);
344 extern int	fsop_root(vfs_t *, vnode_t **);
345 extern int	fsop_statfs(vfs_t *, statvfs64_t *);
346 extern int	fsop_sync(vfs_t *, short, cred_t *);
347 extern int	fsop_vget(vfs_t *, vnode_t **, fid_t *);
348 extern int	fsop_mountroot(vfs_t *, enum whymountroot);
349 extern void	fsop_freefs(vfs_t *);
350 extern int	fsop_sync_by_kind(int, short, cred_t *);
351 extern int	fsop_vnstate(vfs_t *, vnode_t *, vntrans_t);
352 
353 #define	VFS_MOUNT(vfsp, mvp, uap, cr) fsop_mount(vfsp, mvp, uap, cr)
354 #define	VFS_UNMOUNT(vfsp, flag, cr) fsop_unmount(vfsp, flag, cr)
355 #define	VFS_ROOT(vfsp, vpp) fsop_root(vfsp, vpp)
356 #define	VFS_STATVFS(vfsp, sp) fsop_statfs(vfsp, sp)
357 #define	VFS_SYNC(vfsp, flag, cr) fsop_sync(vfsp, flag, cr)
358 #define	VFS_VGET(vfsp, vpp, fidp) fsop_vget(vfsp, vpp, fidp)
359 #define	VFS_MOUNTROOT(vfsp, init) fsop_mountroot(vfsp, init)
360 #define	VFS_FREEVFS(vfsp) fsop_freefs(vfsp)
361 #define	VFS_VNSTATE(vfsp, vn, ns)	fsop_vnstate(vfsp, vn, ns)
362 
363 #define	VFSNAME_MOUNT		"mount"
364 #define	VFSNAME_UNMOUNT		"unmount"
365 #define	VFSNAME_ROOT		"root"
366 #define	VFSNAME_STATVFS		"statvfs"
367 #define	VFSNAME_SYNC		"sync"
368 #define	VFSNAME_VGET		"vget"
369 #define	VFSNAME_MOUNTROOT	"mountroot"
370 #define	VFSNAME_FREEVFS		"freevfs"
371 #define	VFSNAME_VNSTATE		"vnstate"
372 /*
373  * Filesystem type switch table.
374  */
375 
376 typedef struct vfssw {
377 	char		*vsw_name;	/* type name -- max len _ST_FSTYPSZ */
378 	int		(*vsw_init) (int, char *);
379 				/* init routine (for non-loadable fs only) */
380 	int		vsw_flag;	/* flags */
381 	mntopts_t	vsw_optproto;	/* mount options table prototype */
382 	uint_t		vsw_count;	/* count of references */
383 	kmutex_t	vsw_lock;	/* lock to protect vsw_count */
384 	vfsops_t	vsw_vfsops;	/* filesystem operations vector */
385 } vfssw_t;
386 
387 /*
388  * Filesystem type definition record.  All file systems must export a record
389  * of this type through their modlfs structure.  N.B., changing the version
390  * number requires a change in sys/modctl.h.
391  */
392 
393 typedef struct vfsdef_v5 {
394 	int		def_version;	/* structure version, must be first */
395 	char		*name;		/* filesystem type name */
396 	int		(*init) (int, char *);	/* init routine */
397 	int		flags;		/* filesystem flags */
398 	mntopts_t	*optproto;	/* mount options table prototype */
399 } vfsdef_v5;
400 
401 typedef struct vfsdef_v5 vfsdef_t;
402 
403 enum {
404 	VFSDEF_VERSION = 5
405 };
406 
407 /*
408  * flags for vfssw and vfsdef
409  */
410 #define	VSW_HASPROTO	0x01	/* struct has a mount options prototype */
411 #define	VSW_CANRWRO	0x02	/* file system can transition from rw to ro */
412 #define	VSW_CANREMOUNT	0x04	/* file system supports remounts */
413 #define	VSW_NOTZONESAFE	0x08	/* zone_enter(2) should fail for these files */
414 #define	VSW_VOLATILEDEV	0x10	/* vfs_dev can change each time fs is mounted */
415 #define	VSW_STATS	0x20	/* file system can collect stats */
416 #define	VSW_XID		0x40	/* file system supports extended ids */
417 #define	VSW_CANLOFI	0x80	/* file system supports lofi mounts */
418 #define	VSW_ZMOUNT	0x100	/* file system always allowed in a zone */
419 
420 #define	VSW_INSTALLED	0x8000	/* this vsw is associated with a file system */
421 
422 /*
423  * A flag for vfs_setpath().
424  */
425 #define	VFSSP_VERBATIM	0x1	/* do not prefix the supplied path */
426 
427 #if defined(_KERNEL) || defined(_FAKE_KERNEL)
428 
429 /*
430  * Private vfs data, NOT to be used by a file system implementation.
431  */
432 
433 #define	VFS_FEATURE_MAXSZ	4
434 
435 typedef struct vfs_impl {
436 	/* Counted array - Bitmap of vfs features */
437 	uint32_t	vi_featureset[VFS_FEATURE_MAXSZ];
438 	/*
439 	 * Support for statistics on the vnode operations
440 	 */
441 	vsk_anchor_t	*vi_vskap;		/* anchor for vopstats' kstat */
442 	vopstats_t	*vi_fstypevsp;		/* ptr to per-fstype vopstats */
443 	vopstats_t	vi_vopstats;		/* per-mount vnode op stats */
444 
445 	timespec_t	vi_hrctime; 		/* High-res creation time */
446 
447 	zone_ref_t	vi_zone_ref;		/* reference to zone */
448 } vfs_impl_t;
449 
450 /*
451  * Public operations.
452  */
453 struct umounta;
454 struct statvfsa;
455 struct fstatvfsa;
456 
457 void	vfs_freevfsops(vfsops_t *);
458 int	vfs_freevfsops_by_type(int);
459 void	vfs_setops(vfs_t *, vfsops_t *);
460 vfsops_t *vfs_getops(vfs_t *vfsp);
461 int	vfs_matchops(vfs_t *, vfsops_t *);
462 int	vfs_can_sync(vfs_t *vfsp);
463 vfs_t	*vfs_alloc(int);
464 void	vfs_free(vfs_t *);
465 void	vfs_init(vfs_t *vfsp, vfsops_t *, void *);
466 void	vfsimpl_setup(vfs_t *vfsp);
467 void	vfsimpl_teardown(vfs_t *vfsp);
468 void	vn_exists(vnode_t *);
469 void	vn_idle(vnode_t *);
470 void	vn_reclaim(vnode_t *);
471 void	vn_invalid(vnode_t *);
472 
473 int	rootconf(void);
474 int	domount(char *, struct mounta *, vnode_t *, struct cred *,
475 	    struct vfs **);
476 int	dounmount(struct vfs *, int, cred_t *);
477 int	vfs_lock(struct vfs *);
478 int	vfs_rlock(struct vfs *);
479 void	vfs_lock_wait(struct vfs *);
480 void	vfs_rlock_wait(struct vfs *);
481 void	vfs_unlock(struct vfs *);
482 int	vfs_lock_held(struct vfs *);
483 struct	_kthread *vfs_lock_owner(struct vfs *);
484 void	sync(void);
485 void	vfs_sync(int);
486 void	vfs_mountroot(void);
487 void	vfs_add(vnode_t *, struct vfs *, int);
488 void	vfs_remove(struct vfs *);
489 
490 /* VFS feature routines */
491 void	vfs_set_feature(vfs_t *, vfs_feature_t);
492 void	vfs_clear_feature(vfs_t *, vfs_feature_t);
493 int	vfs_has_feature(vfs_t *, vfs_feature_t);
494 void	vfs_propagate_features(vfs_t *, vfs_t *);
495 
496 /* The following functions are not for general use by filesystems */
497 
498 void	vfs_createopttbl(mntopts_t *, const char *);
499 void	vfs_copyopttbl(const mntopts_t *, mntopts_t *);
500 void	vfs_mergeopttbl(const mntopts_t *, const mntopts_t *, mntopts_t *);
501 void	vfs_freeopttbl(mntopts_t *);
502 void	vfs_parsemntopts(mntopts_t *, char *, int);
503 int	vfs_buildoptionstr(const mntopts_t *, char *, int);
504 struct mntopt *vfs_hasopt(const mntopts_t *, const char *);
505 void	vfs_mnttab_modtimeupd(void);
506 
507 void	vfs_clearmntopt(struct vfs *, const char *);
508 void	vfs_setmntopt(struct vfs *, const char *, const char *, int);
509 void	vfs_setresource(struct vfs *, const char *, uint32_t);
510 void	vfs_setmntpoint(struct vfs *, const char *, uint32_t);
511 refstr_t *vfs_getresource(const struct vfs *);
512 refstr_t *vfs_getmntpoint(const struct vfs *);
513 int	vfs_optionisset(const struct vfs *, const char *, char **);
514 int	vfs_settag(uint_t, uint_t, const char *, const char *, cred_t *);
515 int	vfs_clrtag(uint_t, uint_t, const char *, const char *, cred_t *);
516 void	vfs_syncall(void);
517 void	vfsinit(void);
518 void	vfs_unmountall(void);
519 void	vfs_make_fsid(fsid_t *, dev_t, int);
520 void	vfs_addmip(dev_t, struct vfs *);
521 void	vfs_delmip(struct vfs *);
522 int	vfs_devismounted(dev_t);
523 int	vfs_devmounting(dev_t, struct vfs *);
524 int	vfs_opsinuse(vfsops_t *);
525 struct vfs *getvfs(fsid_t *);
526 struct vfs *vfs_dev2vfsp(dev_t);
527 struct vfs *vfs_mntpoint2vfsp(const char *);
528 struct vfssw *allocate_vfssw(const char *);
529 struct vfssw *vfs_getvfssw(const char *);
530 struct vfssw *vfs_getvfsswbyname(const char *);
531 struct vfssw *vfs_getvfsswbyvfsops(vfsops_t *);
532 void	vfs_refvfssw(struct vfssw *);
533 void	vfs_unrefvfssw(struct vfssw *);
534 uint_t	vf_to_stf(uint_t);
535 void	vfs_mnttab_modtime(timespec_t *);
536 void	vfs_mnttab_poll(timespec_t *, struct pollhead **);
537 
538 void	vfs_list_lock(void);
539 void	vfs_list_read_lock(void);
540 void	vfs_list_unlock(void);
541 void	vfs_list_add(struct vfs *);
542 void	vfs_list_remove(struct vfs *);
543 void	vfs_hold(vfs_t *vfsp);
544 void	vfs_rele(vfs_t *vfsp);
545 void	fs_freevfs(vfs_t *);
546 void	vfs_root_redev(vfs_t *vfsp, dev_t ndev, int fstype);
547 
548 int	vfs_zone_change_safe(vfs_t *);
549 
550 int	vfs_get_lofi(vfs_t *, vnode_t **);
551 
552 #define	VFSHASH(maj, min) (((int)((maj)+(min))) & (vfshsz - 1))
553 #define	VFS_ON_LIST(vfsp) \
554 	((vfsp)->vfs_next != (vfsp) && (vfsp)->vfs_next != NULL)
555 
556 /*
557  * Globals.
558  */
559 
560 extern struct vfssw vfssw[];		/* table of filesystem types */
561 extern krwlock_t vfssw_lock;
562 extern char rootfstype[];		/* name of root fstype */
563 extern const int nfstype;		/* # of elements in vfssw array */
564 extern vfsops_t *EIO_vfsops;		/* operations for vfs being torn-down */
565 
566 /*
567  * The following variables are private to the the kernel's vfs layer.  File
568  * system implementations should not access them.
569  */
570 extern struct vfs *rootvfs;		/* ptr to root vfs structure */
571 typedef struct {
572 	struct vfs *rvfs_head;		/* head vfs in chain */
573 	kmutex_t rvfs_lock;		/* mutex protecting this chain */
574 	uint32_t rvfs_len;		/* length of this chain */
575 } rvfs_t;
576 extern rvfs_t *rvfs_list;
577 extern int vfshsz;			/* # of elements in rvfs_head array */
578 extern const mntopts_t vfs_mntopts;	/* globally recognized options */
579 
580 #endif /* defined(_KERNEL) */
581 
582 #define	VFS_HOLD(vfsp) { \
583 	vfs_hold(vfsp); \
584 }
585 
586 #define	VFS_RELE(vfsp)	{ \
587 	vfs_rele(vfsp); \
588 }
589 
590 #define	VFS_INIT(vfsp, op, data) { \
591 	vfs_init((vfsp), (op), (data)); \
592 }
593 
594 
595 #define	VFS_INSTALLED(vfsswp)	(((vfsswp)->vsw_flag & VSW_INSTALLED) != 0)
596 #define	ALLOCATED_VFSSW(vswp)		((vswp)->vsw_name[0] != '\0')
597 #define	RLOCK_VFSSW()			(rw_enter(&vfssw_lock, RW_READER))
598 #define	RUNLOCK_VFSSW()			(rw_exit(&vfssw_lock))
599 #define	WLOCK_VFSSW()			(rw_enter(&vfssw_lock, RW_WRITER))
600 #define	WUNLOCK_VFSSW()			(rw_exit(&vfssw_lock))
601 #define	VFSSW_LOCKED()			(RW_LOCK_HELD(&vfssw_lock))
602 #define	VFSSW_WRITE_LOCKED()		(RW_WRITE_HELD(&vfssw_lock))
603 /*
604  * VFS_SYNC flags.
605  */
606 #define	SYNC_ATTR	0x01		/* sync attributes only */
607 #define	SYNC_CLOSE	0x02		/* close open file */
608 #define	SYNC_ALL	0x04		/* force to sync all fs */
609 
610 #ifdef	__cplusplus
611 }
612 #endif
613 
614 #endif	/* _SYS_VFS_H */
615