xref: /titanic_41/usr/src/uts/common/sys/vfs.h (revision 49d3bc91e27cd871b950d56c01398fa2f2e12ab4)
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 (c) 1988, 2010, Oracle and/or its affiliates. All rights reserved.
23  */
24 
25 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
26 /*	  All Rights Reserved  	*/
27 
28 /*
29  * Portions of this source code were derived from Berkeley 4.3 BSD
30  * under license from the Regents of the University of California.
31  */
32 
33 #ifndef _SYS_VFS_H
34 #define	_SYS_VFS_H
35 
36 #include <sys/zone.h>
37 #include <sys/types.h>
38 #include <sys/t_lock.h>
39 #include <sys/cred.h>
40 #include <sys/vnode.h>
41 #include <sys/statvfs.h>
42 #include <sys/refstr.h>
43 #include <sys/avl.h>
44 #include <sys/time.h>
45 
46 #ifdef	__cplusplus
47 extern "C" {
48 #endif
49 
50 /*
51  * Data associated with mounted file systems.
52  */
53 
54 /*
55  * Operations vector.  This is used internal to the kernel; file systems
56  * supply their list of operations via vfs_setfsops().
57  */
58 
59 typedef struct vfsops vfsops_t;
60 
61 /*
62  * File system identifier. Should be unique (at least per machine).
63  */
64 typedef struct {
65 	int val[2];			/* file system id type */
66 } fsid_t;
67 
68 /*
69  * File identifier.  Should be unique per filesystem on a single
70  * machine.  This is typically called by a stateless file server
71  * in order to generate "file handles".
72  *
73  * Do not change the definition of struct fid ... fid_t without
74  * letting the CacheFS group know about it!  They will have to do at
75  * least two things, in the same change that changes this structure:
76  *   1. change CFSVERSION in usr/src/uts/common/sys/fs/cachefs_fs.h
77  *   2. put the old version # in the canupgrade array
78  *	in cachfs_upgrade() in usr/src/cmd/fs.d/cachefs/fsck/fsck.c
79  * This is necessary because CacheFS stores FIDs on disk.
80  *
81  * Many underlying file systems cast a struct fid into other
82  * file system dependent structures which may require 4 byte alignment.
83  * Because a fid starts with a short it may not be 4 byte aligned, the
84  * fid_pad will force the alignment.
85  */
86 #define	MAXFIDSZ	64
87 #define	OLD_MAXFIDSZ	16
88 
89 typedef struct fid {
90 	union {
91 		long fid_pad;
92 		struct {
93 			ushort_t len;	/* length of data in bytes */
94 			char	data[MAXFIDSZ]; /* data (variable len) */
95 		} _fid;
96 	} un;
97 } fid_t;
98 
99 #ifdef _SYSCALL32
100 /*
101  * Solaris 64 - use old-style cache format with 32-bit aligned fid for on-disk
102  * struct compatibility.
103  */
104 typedef struct fid32 {
105 	union {
106 		int32_t fid_pad;
107 		struct {
108 			uint16_t  len;   /* length of data in bytes */
109 			char    data[MAXFIDSZ]; /* data (variable len) */
110 		} _fid;
111 	} un;
112 } fid32_t;
113 #else /* not _SYSCALL32 */
114 #define	fid32	fid
115 typedef fid_t	fid32_t;
116 #endif /* _SYSCALL32 */
117 
118 #define	fid_len		un._fid.len
119 #define	fid_data	un._fid.data
120 
121 /*
122  * Structure defining a mount option for a filesystem.
123  * option names are found in mntent.h
124  */
125 typedef struct mntopt {
126 	char	*mo_name;	/* option name */
127 	char	**mo_cancel;	/* list of options cancelled by this one */
128 	char	*mo_arg;	/* argument string for this option */
129 	int	mo_flags;	/* flags for this mount option */
130 	void	*mo_data;	/* filesystem specific data */
131 } mntopt_t;
132 
133 /*
134  * Flags that apply to mount options
135  */
136 
137 #define	MO_SET		0x01		/* option is set */
138 #define	MO_NODISPLAY	0x02		/* option not listed in mnttab */
139 #define	MO_HASVALUE	0x04		/* option takes a value */
140 #define	MO_IGNORE	0x08		/* option ignored by parser */
141 #define	MO_DEFAULT	MO_SET		/* option is on by default */
142 #define	MO_TAG		0x10		/* flags a tag set by user program */
143 #define	MO_EMPTY	0x20		/* empty space in option table */
144 
145 #define	VFS_NOFORCEOPT	0x01		/* honor MO_IGNORE (don't set option) */
146 #define	VFS_DISPLAY	0x02		/* Turn off MO_NODISPLAY bit for opt */
147 #define	VFS_NODISPLAY	0x04		/* Turn on MO_NODISPLAY bit for opt */
148 #define	VFS_CREATEOPT	0x08		/* Create the opt if it's not there */
149 
150 /*
151  * Structure holding mount option strings for the mounted file system.
152  */
153 typedef struct mntopts {
154 	uint_t		mo_count;		/* number of entries in table */
155 	mntopt_t	*mo_list;		/* list of mount options */
156 } mntopts_t;
157 
158 /*
159  * The kstat structures associated with the vopstats are kept in an
160  * AVL tree.  This is to avoid the case where a file system does not
161  * use a unique fsid_t for each vfs (e.g., namefs).  In order to do
162  * this, we need a structure that the AVL tree can use that also
163  * references the kstat.
164  * Note that the vks_fsid is generated from the value reported by
165  * VFS_STATVFS().
166  */
167 typedef struct vskstat_anchor {
168 	avl_node_t	vsk_node;	/* Required for use by AVL routines */
169 	kstat_t		*vsk_ksp;	/* kstat structure for vopstats */
170 	ulong_t		vsk_fsid;	/* fsid associated w/this FS */
171 } vsk_anchor_t;
172 
173 extern avl_tree_t	vskstat_tree;
174 extern kmutex_t		vskstat_tree_lock;
175 
176 /*
177  * Structure per mounted file system.  Each mounted file system has
178  * an array of operations and an instance record.
179  *
180  * The file systems are kept on a doubly linked circular list headed by
181  * "rootvfs".
182  * File system implementations should not access this list;
183  * it's intended for use only in the kernel's vfs layer.
184  *
185  * Each zone also has its own list of mounts, containing filesystems mounted
186  * somewhere within the filesystem tree rooted at the zone's rootpath.  The
187  * list is doubly linked to match the global list.
188  *
189  * mnttab locking: the in-kernel mnttab uses the vfs_mntpt, vfs_resource and
190  * vfs_mntopts fields in the vfs_t. mntpt and resource are refstr_ts that
191  * are set at mount time and can only be modified during a remount.
192  * It is safe to read these fields if you can prevent a remount on the vfs,
193  * or through the convenience funcs vfs_getmntpoint() and vfs_getresource().
194  * The mntopts field may only be accessed through the provided convenience
195  * functions, as it is protected by the vfs list lock. Modifying a mount
196  * option requires grabbing the vfs list write lock, which can be a very
197  * high latency lock.
198  */
199 struct zone;		/* from zone.h */
200 struct fem_head;	/* from fem.h */
201 
202 typedef struct vfs {
203 	struct vfs	*vfs_next;		/* next VFS in VFS list */
204 	struct vfs	*vfs_prev;		/* prev VFS in VFS list */
205 
206 /* vfs_op should not be used directly.  Accessor functions are provided */
207 	vfsops_t	*vfs_op;		/* operations on VFS */
208 
209 	struct vnode	*vfs_vnodecovered;	/* vnode mounted on */
210 	uint_t		vfs_flag;		/* flags */
211 	uint_t		vfs_bsize;		/* native block size */
212 	int		vfs_fstype;		/* file system type index */
213 	fsid_t		vfs_fsid;		/* file system id */
214 	void		*vfs_data;		/* private data */
215 	dev_t		vfs_dev;		/* device of mounted VFS */
216 	ulong_t		vfs_bcount;		/* I/O count (accounting) */
217 	struct vfs	*vfs_list;		/* sync list pointer */
218 	struct vfs	*vfs_hash;		/* hash list pointer */
219 	ksema_t		vfs_reflock;		/* mount/unmount/sync lock */
220 	uint_t		vfs_count;		/* vfs reference count */
221 	mntopts_t	vfs_mntopts;		/* options mounted with */
222 	refstr_t	*vfs_resource;		/* mounted resource name */
223 	refstr_t	*vfs_mntpt;		/* mount point name */
224 	time_t		vfs_mtime;		/* time we were mounted */
225 	struct vfs_impl	*vfs_implp;		/* impl specific data */
226 	/*
227 	 * Zones support.  Note that the zone that "owns" the mount isn't
228 	 * necessarily the same as the zone in which the zone is visible.
229 	 * That is, vfs_zone and (vfs_zone_next|vfs_zone_prev) may refer to
230 	 * different zones.
231 	 */
232 	struct zone	*vfs_zone;		/* zone that owns the mount */
233 	struct vfs	*vfs_zone_next;		/* next VFS visible in zone */
234 	struct vfs	*vfs_zone_prev;		/* prev VFS visible in zone */
235 
236 	struct fem_head	*vfs_femhead;		/* fs monitoring */
237 	minor_t		vfs_lofi_minor;		/* minor if lofi mount */
238 } vfs_t;
239 
240 #define	vfs_featureset	vfs_implp->vi_featureset
241 #define	vfs_vskap	vfs_implp->vi_vskap
242 #define	vfs_fstypevsp	vfs_implp->vi_fstypevsp
243 #define	vfs_vopstats	vfs_implp->vi_vopstats
244 #define	vfs_hrctime	vfs_implp->vi_hrctime
245 
246 /*
247  * VFS flags.
248  */
249 #define	VFS_RDONLY	0x01		/* read-only vfs */
250 #define	VFS_NOMNTTAB	0x02		/* vfs not seen in mnttab */
251 #define	VFS_NOSETUID	0x08		/* setuid disallowed */
252 #define	VFS_REMOUNT	0x10		/* modify mount options only */
253 #define	VFS_NOTRUNC	0x20		/* does not truncate long file names */
254 #define	VFS_UNLINKABLE	0x40		/* unlink(2) can be applied to root */
255 #define	VFS_PXFS	0x80		/* clustering: global fs proxy vfs */
256 #define	VFS_UNMOUNTED	0x100		/* file system has been unmounted */
257 #define	VFS_NBMAND	0x200		/* allow non-blocking mandatory locks */
258 #define	VFS_XATTR	0x400		/* fs supports extended attributes */
259 #define	VFS_NODEVICES	0x800		/* device-special files disallowed */
260 #define	VFS_NOEXEC	0x1000		/* executables disallowed */
261 #define	VFS_STATS	0x2000		/* file system can collect stats */
262 #define	VFS_XID		0x4000		/* file system supports extended ids */
263 
264 #define	VFS_NORESOURCE	"unspecified_resource"
265 #define	VFS_NOMNTPT	"unspecified_mountpoint"
266 
267 /*
268  * VFS features are implemented as bits set in the vfs_t.
269  * The vfs_feature_t typedef is a 64-bit number that will translate
270  * into an element in an array of bitmaps and a bit in that element.
271  * Developers must not depend on the implementation of this and
272  * need to use vfs_has_feature()/vfs_set_feature() routines.
273  */
274 typedef	uint64_t	vfs_feature_t;
275 
276 #define	VFSFT_XVATTR		0x100000001	/* Supports xvattr for attrs */
277 #define	VFSFT_CASEINSENSITIVE	0x100000002	/* Supports case-insensitive */
278 #define	VFSFT_NOCASESENSITIVE	0x100000004	/* NOT case-sensitive */
279 #define	VFSFT_DIRENTFLAGS	0x100000008	/* Supports dirent flags */
280 #define	VFSFT_ACLONCREATE	0x100000010	/* Supports ACL on create */
281 #define	VFSFT_ACEMASKONACCESS	0x100000020	/* Can use ACEMASK for access */
282 #define	VFSFT_SYSATTR_VIEWS	0x100000040	/* Supports sysattr view i/f */
283 #define	VFSFT_ACCESS_FILTER	0x100000080	/* dirents filtered by access */
284 #define	VFSFT_REPARSE		0x100000100	/* Supports reparse point */
285 #define	VFSFT_ZEROCOPY_SUPPORTED	0x100000200
286 				/* Support loaning /returning cache buffer */
287 /*
288  * Argument structure for mount(2).
289  *
290  * Flags are defined in <sys/mount.h>.
291  *
292  * Note that if the MS_SYSSPACE bit is set in flags, the pointer fields in
293  * this structure are to be interpreted as kernel addresses.  File systems
294  * should be prepared for this possibility.
295  */
296 struct mounta {
297 	char	*spec;
298 	char	*dir;
299 	int	flags;
300 	char	*fstype;
301 	char	*dataptr;
302 	int	datalen;
303 	char	*optptr;
304 	int	optlen;
305 };
306 
307 /*
308  * Reasons for calling the vfs_mountroot() operation.
309  */
310 enum whymountroot { ROOT_INIT, ROOT_REMOUNT, ROOT_UNMOUNT};
311 typedef enum whymountroot whymountroot_t;
312 
313 /*
314  * Reasons for calling the VFS_VNSTATE():
315  */
316 enum vntrans {
317 	VNTRANS_EXISTS,
318 	VNTRANS_IDLED,
319 	VNTRANS_RECLAIMED,
320 	VNTRANS_DESTROYED
321 };
322 typedef enum vntrans vntrans_t;
323 
324 /*
325  * VFS_OPS defines all the vfs operations.  It is used to define
326  * the vfsops structure (below) and the fs_func_p union (vfs_opreg.h).
327  */
328 #define	VFS_OPS								\
329 	int	(*vfs_mount)(vfs_t *, vnode_t *, struct mounta *, cred_t *); \
330 	int	(*vfs_unmount)(vfs_t *, int, cred_t *);			\
331 	int	(*vfs_root)(vfs_t *, vnode_t **);			\
332 	int	(*vfs_statvfs)(vfs_t *, statvfs64_t *);			\
333 	int	(*vfs_sync)(vfs_t *, short, cred_t *);			\
334 	int	(*vfs_vget)(vfs_t *, vnode_t **, fid_t *);		\
335 	int	(*vfs_mountroot)(vfs_t *, enum whymountroot);		\
336 	void	(*vfs_freevfs)(vfs_t *);				\
337 	int	(*vfs_vnstate)(vfs_t *, vnode_t *, vntrans_t)	/* NB: No ";" */
338 
339 /*
340  * Operations supported on virtual file system.
341  */
342 struct vfsops {
343 	VFS_OPS;	/* Signature of all vfs operations (vfsops) */
344 };
345 
346 extern int	fsop_mount(vfs_t *, vnode_t *, struct mounta *, cred_t *);
347 extern int	fsop_unmount(vfs_t *, int, cred_t *);
348 extern int	fsop_root(vfs_t *, vnode_t **);
349 extern int	fsop_statfs(vfs_t *, statvfs64_t *);
350 extern int	fsop_sync(vfs_t *, short, cred_t *);
351 extern int	fsop_vget(vfs_t *, vnode_t **, fid_t *);
352 extern int	fsop_mountroot(vfs_t *, enum whymountroot);
353 extern void	fsop_freefs(vfs_t *);
354 extern int	fsop_sync_by_kind(int, short, cred_t *);
355 extern int	fsop_vnstate(vfs_t *, vnode_t *, vntrans_t);
356 
357 #define	VFS_MOUNT(vfsp, mvp, uap, cr) fsop_mount(vfsp, mvp, uap, cr)
358 #define	VFS_UNMOUNT(vfsp, flag, cr) fsop_unmount(vfsp, flag, cr)
359 #define	VFS_ROOT(vfsp, vpp) fsop_root(vfsp, vpp)
360 #define	VFS_STATVFS(vfsp, sp) fsop_statfs(vfsp, sp)
361 #define	VFS_SYNC(vfsp, flag, cr) fsop_sync(vfsp, flag, cr)
362 #define	VFS_VGET(vfsp, vpp, fidp) fsop_vget(vfsp, vpp, fidp)
363 #define	VFS_MOUNTROOT(vfsp, init) fsop_mountroot(vfsp, init)
364 #define	VFS_FREEVFS(vfsp) fsop_freefs(vfsp)
365 #define	VFS_VNSTATE(vfsp, vn, ns)	fsop_vnstate(vfsp, vn, ns)
366 
367 #define	VFSNAME_MOUNT		"mount"
368 #define	VFSNAME_UNMOUNT		"unmount"
369 #define	VFSNAME_ROOT		"root"
370 #define	VFSNAME_STATVFS		"statvfs"
371 #define	VFSNAME_SYNC		"sync"
372 #define	VFSNAME_VGET		"vget"
373 #define	VFSNAME_MOUNTROOT	"mountroot"
374 #define	VFSNAME_FREEVFS		"freevfs"
375 #define	VFSNAME_VNSTATE		"vnstate"
376 /*
377  * Filesystem type switch table.
378  */
379 
380 typedef struct vfssw {
381 	char		*vsw_name;	/* type name -- max len _ST_FSTYPSZ */
382 	int		(*vsw_init) (int, char *);
383 				/* init routine (for non-loadable fs only) */
384 	int		vsw_flag;	/* flags */
385 	mntopts_t	vsw_optproto;	/* mount options table prototype */
386 	uint_t		vsw_count;	/* count of references */
387 	kmutex_t	vsw_lock;	/* lock to protect vsw_count */
388 	vfsops_t	vsw_vfsops;	/* filesystem operations vector */
389 } vfssw_t;
390 
391 /*
392  * Filesystem type definition record.  All file systems must export a record
393  * of this type through their modlfs structure.  N.B., changing the version
394  * number requires a change in sys/modctl.h.
395  */
396 
397 typedef struct vfsdef_v5 {
398 	int		def_version;	/* structure version, must be first */
399 	char		*name;		/* filesystem type name */
400 	int		(*init) (int, char *);	/* init routine */
401 	int		flags;		/* filesystem flags */
402 	mntopts_t	*optproto;	/* mount options table prototype */
403 } vfsdef_v5;
404 
405 typedef struct vfsdef_v5 vfsdef_t;
406 
407 enum {
408 	VFSDEF_VERSION = 5
409 };
410 
411 /*
412  * flags for vfssw and vfsdef
413  */
414 #define	VSW_HASPROTO	0x01	/* struct has a mount options prototype */
415 #define	VSW_CANRWRO	0x02	/* file system can transition from rw to ro */
416 #define	VSW_CANREMOUNT	0x04	/* file system supports remounts */
417 #define	VSW_NOTZONESAFE	0x08	/* zone_enter(2) should fail for these files */
418 #define	VSW_VOLATILEDEV	0x10	/* vfs_dev can change each time fs is mounted */
419 #define	VSW_STATS	0x20	/* file system can collect stats */
420 #define	VSW_XID		0x40	/* file system supports extended ids */
421 #define	VSW_CANLOFI	0x80	/* file system supports lofi mounts */
422 #define	VSW_ZMOUNT	0x100	/* file system always allowed in a zone */
423 
424 #define	VSW_INSTALLED	0x8000	/* this vsw is associated with a file system */
425 
426 /*
427  * A flag for vfs_setpath().
428  */
429 #define	VFSSP_VERBATIM	0x1	/* do not prefix the supplied path */
430 
431 #if defined(_KERNEL)
432 
433 /*
434  * Private vfs data, NOT to be used by a file system implementation.
435  */
436 
437 #define	VFS_FEATURE_MAXSZ	4
438 
439 typedef struct vfs_impl {
440 	/* Counted array - Bitmap of vfs features */
441 	uint32_t	vi_featureset[VFS_FEATURE_MAXSZ];
442 	/*
443 	 * Support for statistics on the vnode operations
444 	 */
445 	vsk_anchor_t	*vi_vskap;		/* anchor for vopstats' kstat */
446 	vopstats_t	*vi_fstypevsp;		/* ptr to per-fstype vopstats */
447 	vopstats_t	vi_vopstats;		/* per-mount vnode op stats */
448 
449 	timespec_t	vi_hrctime; 		/* High-res creation time */
450 
451 	zone_ref_t	vi_zone_ref;		/* reference to zone */
452 } vfs_impl_t;
453 
454 /*
455  * Public operations.
456  */
457 struct umounta;
458 struct statvfsa;
459 struct fstatvfsa;
460 
461 void	vfs_freevfsops(vfsops_t *);
462 int	vfs_freevfsops_by_type(int);
463 void	vfs_setops(vfs_t *, vfsops_t *);
464 vfsops_t *vfs_getops(vfs_t *vfsp);
465 int	vfs_matchops(vfs_t *, vfsops_t *);
466 int	vfs_can_sync(vfs_t *vfsp);
467 vfs_t	*vfs_alloc(int);
468 void	vfs_free(vfs_t *);
469 void	vfs_init(vfs_t *vfsp, vfsops_t *, void *);
470 void	vfsimpl_setup(vfs_t *vfsp);
471 void	vfsimpl_teardown(vfs_t *vfsp);
472 void	vn_exists(vnode_t *);
473 void	vn_idle(vnode_t *);
474 void	vn_reclaim(vnode_t *);
475 void	vn_invalid(vnode_t *);
476 
477 int	rootconf(void);
478 int	svm_rootconf(void);
479 int	domount(char *, struct mounta *, vnode_t *, struct cred *,
480 	    struct vfs **);
481 int	dounmount(struct vfs *, int, cred_t *);
482 int	vfs_lock(struct vfs *);
483 int	vfs_rlock(struct vfs *);
484 void	vfs_lock_wait(struct vfs *);
485 void	vfs_rlock_wait(struct vfs *);
486 void	vfs_unlock(struct vfs *);
487 int	vfs_lock_held(struct vfs *);
488 struct	_kthread *vfs_lock_owner(struct vfs *);
489 void	sync(void);
490 void	vfs_sync(int);
491 void	vfs_mountroot(void);
492 void	vfs_add(vnode_t *, struct vfs *, int);
493 void	vfs_remove(struct vfs *);
494 
495 /* VFS feature routines */
496 void	vfs_set_feature(vfs_t *, vfs_feature_t);
497 void	vfs_clear_feature(vfs_t *, vfs_feature_t);
498 int	vfs_has_feature(vfs_t *, vfs_feature_t);
499 void	vfs_propagate_features(vfs_t *, vfs_t *);
500 
501 /* The following functions are not for general use by filesystems */
502 
503 void	vfs_createopttbl(mntopts_t *, const char *);
504 void	vfs_copyopttbl(const mntopts_t *, mntopts_t *);
505 void	vfs_mergeopttbl(const mntopts_t *, const mntopts_t *, mntopts_t *);
506 void	vfs_freeopttbl(mntopts_t *);
507 void	vfs_parsemntopts(mntopts_t *, char *, int);
508 int	vfs_buildoptionstr(const mntopts_t *, char *, int);
509 struct mntopt *vfs_hasopt(const mntopts_t *, const char *);
510 void	vfs_mnttab_modtimeupd(void);
511 
512 void	vfs_clearmntopt(struct vfs *, const char *);
513 void	vfs_setmntopt(struct vfs *, const char *, const char *, int);
514 void	vfs_setresource(struct vfs *, const char *, uint32_t);
515 void	vfs_setmntpoint(struct vfs *, const char *, uint32_t);
516 refstr_t *vfs_getresource(const struct vfs *);
517 refstr_t *vfs_getmntpoint(const struct vfs *);
518 int	vfs_optionisset(const struct vfs *, const char *, char **);
519 int	vfs_settag(uint_t, uint_t, const char *, const char *, cred_t *);
520 int	vfs_clrtag(uint_t, uint_t, const char *, const char *, cred_t *);
521 void	vfs_syncall(void);
522 void	vfs_syncprogress(void);
523 void	vfsinit(void);
524 void	vfs_unmountall(void);
525 void	vfs_make_fsid(fsid_t *, dev_t, int);
526 void	vfs_addmip(dev_t, struct vfs *);
527 void	vfs_delmip(struct vfs *);
528 int	vfs_devismounted(dev_t);
529 int	vfs_devmounting(dev_t, struct vfs *);
530 int	vfs_opsinuse(vfsops_t *);
531 struct vfs *getvfs(fsid_t *);
532 struct vfs *vfs_dev2vfsp(dev_t);
533 struct vfs *vfs_mntpoint2vfsp(const char *);
534 struct vfssw *allocate_vfssw(const char *);
535 struct vfssw *vfs_getvfssw(const char *);
536 struct vfssw *vfs_getvfsswbyname(const char *);
537 struct vfssw *vfs_getvfsswbyvfsops(vfsops_t *);
538 void	vfs_refvfssw(struct vfssw *);
539 void	vfs_unrefvfssw(struct vfssw *);
540 uint_t	vf_to_stf(uint_t);
541 void	vfs_mnttab_modtime(timespec_t *);
542 void	vfs_mnttab_poll(timespec_t *, struct pollhead **);
543 
544 void	vfs_list_lock(void);
545 void	vfs_list_read_lock(void);
546 void	vfs_list_unlock(void);
547 void	vfs_list_add(struct vfs *);
548 void	vfs_list_remove(struct vfs *);
549 void	vfs_hold(vfs_t *vfsp);
550 void	vfs_rele(vfs_t *vfsp);
551 void	fs_freevfs(vfs_t *);
552 void	vfs_root_redev(vfs_t *vfsp, dev_t ndev, int fstype);
553 
554 int	vfs_zone_change_safe(vfs_t *);
555 
556 int	vfs_get_lofi(vfs_t *, vnode_t **);
557 
558 #define	VFSHASH(maj, min) (((int)((maj)+(min))) & (vfshsz - 1))
559 #define	VFS_ON_LIST(vfsp) \
560 	((vfsp)->vfs_next != (vfsp) && (vfsp)->vfs_next != NULL)
561 
562 /*
563  * Globals.
564  */
565 
566 extern struct vfssw vfssw[];		/* table of filesystem types */
567 extern krwlock_t vfssw_lock;
568 extern char rootfstype[];		/* name of root fstype */
569 extern const int nfstype;		/* # of elements in vfssw array */
570 extern vfsops_t *EIO_vfsops;		/* operations for vfs being torn-down */
571 
572 /*
573  * The following variables are private to the the kernel's vfs layer.  File
574  * system implementations should not access them.
575  */
576 extern struct vfs *rootvfs;		/* ptr to root vfs structure */
577 typedef struct {
578 	struct vfs *rvfs_head;		/* head vfs in chain */
579 	kmutex_t rvfs_lock;		/* mutex protecting this chain */
580 	uint32_t rvfs_len;		/* length of this chain */
581 } rvfs_t;
582 extern rvfs_t *rvfs_list;
583 extern int vfshsz;			/* # of elements in rvfs_head array */
584 extern const mntopts_t vfs_mntopts;	/* globally recognized options */
585 
586 #endif /* defined(_KERNEL) */
587 
588 #define	VFS_HOLD(vfsp) { \
589 	vfs_hold(vfsp); \
590 }
591 
592 #define	VFS_RELE(vfsp)	{ \
593 	vfs_rele(vfsp); \
594 }
595 
596 #define	VFS_INIT(vfsp, op, data) { \
597 	vfs_init((vfsp), (op), (data)); \
598 }
599 
600 
601 #define	VFS_INSTALLED(vfsswp)	(((vfsswp)->vsw_flag & VSW_INSTALLED) != 0)
602 #define	ALLOCATED_VFSSW(vswp)		((vswp)->vsw_name[0] != '\0')
603 #define	RLOCK_VFSSW()			(rw_enter(&vfssw_lock, RW_READER))
604 #define	RUNLOCK_VFSSW()			(rw_exit(&vfssw_lock))
605 #define	WLOCK_VFSSW()			(rw_enter(&vfssw_lock, RW_WRITER))
606 #define	WUNLOCK_VFSSW()			(rw_exit(&vfssw_lock))
607 #define	VFSSW_LOCKED()			(RW_LOCK_HELD(&vfssw_lock))
608 #define	VFSSW_WRITE_LOCKED()		(RW_WRITE_HELD(&vfssw_lock))
609 /*
610  * VFS_SYNC flags.
611  */
612 #define	SYNC_ATTR	0x01		/* sync attributes only */
613 #define	SYNC_CLOSE	0x02		/* close open file */
614 #define	SYNC_ALL	0x04		/* force to sync all fs */
615 
616 #ifdef	__cplusplus
617 }
618 #endif
619 
620 #endif	/* _SYS_VFS_H */
621