xref: /freebsd/sys/sys/mount.h (revision e17f5b1d)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1989, 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)mount.h	8.21 (Berkeley) 5/20/95
32  * $FreeBSD$
33  */
34 
35 #ifndef _SYS_MOUNT_H_
36 #define _SYS_MOUNT_H_
37 
38 #include <sys/ucred.h>
39 #include <sys/queue.h>
40 #ifdef _KERNEL
41 #include <sys/lock.h>
42 #include <sys/lockmgr.h>
43 #include <sys/tslog.h>
44 #include <sys/_mutex.h>
45 #include <sys/_sx.h>
46 #endif
47 
48 /*
49  * NOTE: When changing statfs structure, mount structure, MNT_* flags or
50  * MNTK_* flags also update DDB show mount command in vfs_subr.c.
51  */
52 
53 typedef struct fsid { int32_t val[2]; } fsid_t;	/* filesystem id type */
54 
55 #define fsidcmp(a, b) memcmp((a), (b), sizeof(fsid_t))
56 
57 /*
58  * File identifier.
59  * These are unique per filesystem on a single machine.
60  *
61  * Note that the offset of fid_data is 4 bytes, so care must be taken to avoid
62  * undefined behavior accessing unaligned fields within an embedded struct.
63  */
64 #define	MAXFIDSZ	16
65 
66 struct fid {
67 	u_short		fid_len;		/* length of data in bytes */
68 	u_short		fid_data0;		/* force longword alignment */
69 	char		fid_data[MAXFIDSZ];	/* data (variable length) */
70 };
71 
72 /*
73  * filesystem statistics
74  */
75 #define	MFSNAMELEN	16		/* length of type name including null */
76 #define	MNAMELEN	1024		/* size of on/from name bufs */
77 #define	STATFS_VERSION	0x20140518	/* current version number */
78 struct statfs {
79 	uint32_t f_version;		/* structure version number */
80 	uint32_t f_type;		/* type of filesystem */
81 	uint64_t f_flags;		/* copy of mount exported flags */
82 	uint64_t f_bsize;		/* filesystem fragment size */
83 	uint64_t f_iosize;		/* optimal transfer block size */
84 	uint64_t f_blocks;		/* total data blocks in filesystem */
85 	uint64_t f_bfree;		/* free blocks in filesystem */
86 	int64_t	 f_bavail;		/* free blocks avail to non-superuser */
87 	uint64_t f_files;		/* total file nodes in filesystem */
88 	int64_t	 f_ffree;		/* free nodes avail to non-superuser */
89 	uint64_t f_syncwrites;		/* count of sync writes since mount */
90 	uint64_t f_asyncwrites;		/* count of async writes since mount */
91 	uint64_t f_syncreads;		/* count of sync reads since mount */
92 	uint64_t f_asyncreads;		/* count of async reads since mount */
93 	uint64_t f_spare[10];		/* unused spare */
94 	uint32_t f_namemax;		/* maximum filename length */
95 	uid_t	  f_owner;		/* user that mounted the filesystem */
96 	fsid_t	  f_fsid;		/* filesystem id */
97 	char	  f_charspare[80];	    /* spare string space */
98 	char	  f_fstypename[MFSNAMELEN]; /* filesystem type name */
99 	char	  f_mntfromname[MNAMELEN];  /* mounted filesystem */
100 	char	  f_mntonname[MNAMELEN];    /* directory on which mounted */
101 };
102 
103 #if defined(_WANT_FREEBSD11_STATFS) || defined(_KERNEL)
104 #define	FREEBSD11_STATFS_VERSION	0x20030518 /* current version number */
105 struct freebsd11_statfs {
106 	uint32_t f_version;		/* structure version number */
107 	uint32_t f_type;		/* type of filesystem */
108 	uint64_t f_flags;		/* copy of mount exported flags */
109 	uint64_t f_bsize;		/* filesystem fragment size */
110 	uint64_t f_iosize;		/* optimal transfer block size */
111 	uint64_t f_blocks;		/* total data blocks in filesystem */
112 	uint64_t f_bfree;		/* free blocks in filesystem */
113 	int64_t	 f_bavail;		/* free blocks avail to non-superuser */
114 	uint64_t f_files;		/* total file nodes in filesystem */
115 	int64_t	 f_ffree;		/* free nodes avail to non-superuser */
116 	uint64_t f_syncwrites;		/* count of sync writes since mount */
117 	uint64_t f_asyncwrites;		/* count of async writes since mount */
118 	uint64_t f_syncreads;		/* count of sync reads since mount */
119 	uint64_t f_asyncreads;		/* count of async reads since mount */
120 	uint64_t f_spare[10];		/* unused spare */
121 	uint32_t f_namemax;		/* maximum filename length */
122 	uid_t	  f_owner;		/* user that mounted the filesystem */
123 	fsid_t	  f_fsid;		/* filesystem id */
124 	char	  f_charspare[80];	/* spare string space */
125 	char	  f_fstypename[16];	/* filesystem type name */
126 	char	  f_mntfromname[88];	/* mounted filesystem */
127 	char	  f_mntonname[88];	/* directory on which mounted */
128 };
129 #endif /* _WANT_FREEBSD11_STATFS || _KERNEL */
130 
131 #ifdef _KERNEL
132 #define	OMFSNAMELEN	16	/* length of fs type name, including null */
133 #define	OMNAMELEN	(88 - 2 * sizeof(long))	/* size of on/from name bufs */
134 
135 /* XXX getfsstat.2 is out of date with write and read counter changes here. */
136 /* XXX statfs.2 is out of date with read counter changes here. */
137 struct ostatfs {
138 	long	f_spare2;		/* placeholder */
139 	long	f_bsize;		/* fundamental filesystem block size */
140 	long	f_iosize;		/* optimal transfer block size */
141 	long	f_blocks;		/* total data blocks in filesystem */
142 	long	f_bfree;		/* free blocks in fs */
143 	long	f_bavail;		/* free blocks avail to non-superuser */
144 	long	f_files;		/* total file nodes in filesystem */
145 	long	f_ffree;		/* free file nodes in fs */
146 	fsid_t	f_fsid;			/* filesystem id */
147 	uid_t	f_owner;		/* user that mounted the filesystem */
148 	int	f_type;			/* type of filesystem */
149 	int	f_flags;		/* copy of mount exported flags */
150 	long	f_syncwrites;		/* count of sync writes since mount */
151 	long	f_asyncwrites;		/* count of async writes since mount */
152 	char	f_fstypename[OMFSNAMELEN]; /* fs type name */
153 	char	f_mntonname[OMNAMELEN];	/* directory on which mounted */
154 	long	f_syncreads;		/* count of sync reads since mount */
155 	long	f_asyncreads;		/* count of async reads since mount */
156 	short	f_spares1;		/* unused spare */
157 	char	f_mntfromname[OMNAMELEN];/* mounted filesystem */
158 	short	f_spares2;		/* unused spare */
159 	/*
160 	 * XXX on machines where longs are aligned to 8-byte boundaries, there
161 	 * is an unnamed int32_t here.  This spare was after the apparent end
162 	 * of the struct until we bit off the read counters from f_mntonname.
163 	 */
164 	long	f_spare[2];		/* unused spare */
165 };
166 
167 TAILQ_HEAD(vnodelst, vnode);
168 
169 /* Mount options list */
170 TAILQ_HEAD(vfsoptlist, vfsopt);
171 struct vfsopt {
172 	TAILQ_ENTRY(vfsopt) link;
173 	char	*name;
174 	void	*value;
175 	int	len;
176 	int	pos;
177 	int	seen;
178 };
179 
180 /*
181  * Structure per mounted filesystem.  Each mounted filesystem has an
182  * array of operations and an instance record.  The filesystems are
183  * put on a doubly linked list.
184  *
185  * Lock reference:
186  * 	l - mnt_listmtx
187  *	m - mountlist_mtx
188  *	i - interlock
189  *	v - vnode freelist mutex
190  *
191  * Unmarked fields are considered stable as long as a ref is held.
192  *
193  */
194 struct mount {
195 	struct mtx	mnt_mtx;		/* mount structure interlock */
196 	int		mnt_gen;		/* struct mount generation */
197 #define	mnt_startzero	mnt_list
198 	TAILQ_ENTRY(mount) mnt_list;		/* (m) mount list */
199 	struct vfsops	*mnt_op;		/* operations on fs */
200 	struct vfsconf	*mnt_vfc;		/* configuration info */
201 	struct vnode	*mnt_vnodecovered;	/* vnode we mounted on */
202 	struct vnode	*mnt_syncer;		/* syncer vnode */
203 	int		mnt_ref;		/* (i) Reference count */
204 	struct vnodelst	mnt_nvnodelist;		/* (i) list of vnodes */
205 	int		mnt_nvnodelistsize;	/* (i) # of vnodes */
206 	int		mnt_writeopcount;	/* (i) write syscalls pending */
207 	int		mnt_kern_flag;		/* (i) kernel only flags */
208 	uint64_t	mnt_flag;		/* (i) flags shared with user */
209 	struct vfsoptlist *mnt_opt;		/* current mount options */
210 	struct vfsoptlist *mnt_optnew;		/* new options passed to fs */
211 	int		mnt_maxsymlinklen;	/* max size of short symlink */
212 	struct statfs	mnt_stat;		/* cache of filesystem stats */
213 	struct ucred	*mnt_cred;		/* credentials of mounter */
214 	void *		mnt_data;		/* private data */
215 	time_t		mnt_time;		/* last time written*/
216 	int		mnt_iosize_max;		/* max size for clusters, etc */
217 	struct netexport *mnt_export;		/* export list */
218 	struct label	*mnt_label;		/* MAC label for the fs */
219 	u_int		mnt_hashseed;		/* Random seed for vfs_hash */
220 	int		mnt_lockref;		/* (i) Lock reference count */
221 	int		mnt_secondary_writes;   /* (i) # of secondary writes */
222 	int		mnt_secondary_accwrites;/* (i) secondary wr. starts */
223 	struct thread	*mnt_susp_owner;	/* (i) thread owning suspension */
224 #define	mnt_endzero	mnt_gjprovider
225 	char		*mnt_gjprovider;	/* gjournal provider name */
226 	struct mtx	mnt_listmtx;
227 	struct vnodelst	mnt_lazyvnodelist;	/* (l) list of lazy vnodes */
228 	int		mnt_lazyvnodelistsize;	/* (l) # of lazy vnodes */
229 	struct lock	mnt_explock;		/* vfs_export walkers lock */
230 	TAILQ_ENTRY(mount) mnt_upper_link;	/* (m) we in the all uppers */
231 	TAILQ_HEAD(, mount) mnt_uppers;		/* (m) upper mounts over us*/
232 	int __aligned(CACHE_LINE_SIZE)	mnt_vfs_ops;/* (i) pending vfs ops */
233 	int		*mnt_thread_in_ops_pcpu;
234 	int		*mnt_ref_pcpu;
235 	int		*mnt_lockref_pcpu;
236 	int		*mnt_writeopcount_pcpu;
237 	struct vnode	*mnt_rootvnode;
238 };
239 
240 /*
241  * Definitions for MNT_VNODE_FOREACH_ALL.
242  */
243 struct vnode *__mnt_vnode_next_all(struct vnode **mvp, struct mount *mp);
244 struct vnode *__mnt_vnode_first_all(struct vnode **mvp, struct mount *mp);
245 void          __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp);
246 
247 #define MNT_VNODE_FOREACH_ALL(vp, mp, mvp)				\
248 	for (vp = __mnt_vnode_first_all(&(mvp), (mp));			\
249 		(vp) != NULL; vp = __mnt_vnode_next_all(&(mvp), (mp)))
250 
251 #define MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp)				\
252 	do {								\
253 		MNT_ILOCK(mp);						\
254 		__mnt_vnode_markerfree_all(&(mvp), (mp));		\
255 		/* MNT_IUNLOCK(mp); -- done in above function */	\
256 		mtx_assert(MNT_MTX(mp), MA_NOTOWNED);			\
257 	} while (0)
258 
259 /*
260  * Definitions for MNT_VNODE_FOREACH_LAZY.
261  */
262 typedef int mnt_lazy_cb_t(struct vnode *, void *);
263 struct vnode *__mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp,
264     mnt_lazy_cb_t *cb, void *cbarg);
265 struct vnode *__mnt_vnode_first_lazy(struct vnode **mvp, struct mount *mp,
266     mnt_lazy_cb_t *cb, void *cbarg);
267 void          __mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp);
268 
269 #define MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, cb, cbarg)			\
270 	for (vp = __mnt_vnode_first_lazy(&(mvp), (mp), (cb), (cbarg));	\
271 		(vp) != NULL; 						\
272 		vp = __mnt_vnode_next_lazy(&(mvp), (mp), (cb), (cbarg)))
273 
274 #define MNT_VNODE_FOREACH_LAZY_ABORT(mp, mvp)				\
275 	__mnt_vnode_markerfree_lazy(&(mvp), (mp))
276 
277 #define	MNT_ILOCK(mp)	mtx_lock(&(mp)->mnt_mtx)
278 #define	MNT_ITRYLOCK(mp) mtx_trylock(&(mp)->mnt_mtx)
279 #define	MNT_IUNLOCK(mp)	mtx_unlock(&(mp)->mnt_mtx)
280 #define	MNT_MTX(mp)	(&(mp)->mnt_mtx)
281 
282 #define	MNT_REF(mp)	do {						\
283 	mtx_assert(MNT_MTX(mp), MA_OWNED);				\
284 	mp->mnt_ref++;							\
285 } while (0)
286 #define	MNT_REL(mp)	do {						\
287 	mtx_assert(MNT_MTX(mp), MA_OWNED);				\
288 	(mp)->mnt_ref--;						\
289 	if ((mp)->mnt_vfs_ops && (mp)->mnt_ref < 0)		\
290 		vfs_dump_mount_counters(mp);				\
291 	if ((mp)->mnt_ref == 0 && (mp)->mnt_vfs_ops)		\
292 		wakeup((mp));						\
293 } while (0)
294 
295 #endif /* _KERNEL */
296 
297 /*
298  * User specifiable flags, stored in mnt_flag.
299  */
300 #define	MNT_RDONLY	0x0000000000000001ULL /* read only filesystem */
301 #define	MNT_SYNCHRONOUS	0x0000000000000002ULL /* fs written synchronously */
302 #define	MNT_NOEXEC	0x0000000000000004ULL /* can't exec from filesystem */
303 #define	MNT_NOSUID	0x0000000000000008ULL /* don't honor setuid fs bits */
304 #define	MNT_NFS4ACLS	0x0000000000000010ULL /* enable NFS version 4 ACLs */
305 #define	MNT_UNION	0x0000000000000020ULL /* union with underlying fs */
306 #define	MNT_ASYNC	0x0000000000000040ULL /* fs written asynchronously */
307 #define	MNT_SUIDDIR	0x0000000000100000ULL /* special SUID dir handling */
308 #define	MNT_SOFTDEP	0x0000000000200000ULL /* using soft updates */
309 #define	MNT_NOSYMFOLLOW	0x0000000000400000ULL /* do not follow symlinks */
310 #define	MNT_GJOURNAL	0x0000000002000000ULL /* GEOM journal support enabled */
311 #define	MNT_MULTILABEL	0x0000000004000000ULL /* MAC support for objects */
312 #define	MNT_ACLS	0x0000000008000000ULL /* ACL support enabled */
313 #define	MNT_NOATIME	0x0000000010000000ULL /* dont update file access time */
314 #define	MNT_NOCLUSTERR	0x0000000040000000ULL /* disable cluster read */
315 #define	MNT_NOCLUSTERW	0x0000000080000000ULL /* disable cluster write */
316 #define	MNT_SUJ		0x0000000100000000ULL /* using journaled soft updates */
317 #define	MNT_AUTOMOUNTED	0x0000000200000000ULL /* mounted by automountd(8) */
318 #define	MNT_UNTRUSTED	0x0000000800000000ULL /* filesys metadata untrusted */
319 
320 /*
321  * NFS export related mount flags.
322  */
323 #define	MNT_EXRDONLY	0x0000000000000080ULL	/* exported read only */
324 #define	MNT_EXPORTED	0x0000000000000100ULL	/* filesystem is exported */
325 #define	MNT_DEFEXPORTED	0x0000000000000200ULL	/* exported to the world */
326 #define	MNT_EXPORTANON	0x0000000000000400ULL	/* anon uid mapping for all */
327 #define	MNT_EXKERB	0x0000000000000800ULL	/* exported with Kerberos */
328 #define	MNT_EXPUBLIC	0x0000000020000000ULL	/* public export (WebNFS) */
329 
330 /*
331  * Flags set by internal operations,
332  * but visible to the user.
333  * XXX some of these are not quite right.. (I've never seen the root flag set)
334  */
335 #define	MNT_LOCAL	0x0000000000001000ULL /* filesystem is stored locally */
336 #define	MNT_QUOTA	0x0000000000002000ULL /* quotas are enabled on fs */
337 #define	MNT_ROOTFS	0x0000000000004000ULL /* identifies the root fs */
338 #define	MNT_USER	0x0000000000008000ULL /* mounted by a user */
339 #define	MNT_IGNORE	0x0000000000800000ULL /* do not show entry in df */
340 #define	MNT_VERIFIED	0x0000000400000000ULL /* filesystem is verified */
341 
342 /*
343  * Mask of flags that are visible to statfs().
344  * XXX I think that this could now become (~(MNT_CMDFLAGS))
345  * but the 'mount' program may need changing to handle this.
346  */
347 #define	MNT_VISFLAGMASK	(MNT_RDONLY	| MNT_SYNCHRONOUS | MNT_NOEXEC	| \
348 			MNT_NOSUID	| MNT_UNION	| MNT_SUJ	| \
349 			MNT_ASYNC	| MNT_EXRDONLY	| MNT_EXPORTED	| \
350 			MNT_DEFEXPORTED	| MNT_EXPORTANON| MNT_EXKERB	| \
351 			MNT_LOCAL	| MNT_USER	| MNT_QUOTA	| \
352 			MNT_ROOTFS	| MNT_NOATIME	| MNT_NOCLUSTERR| \
353 			MNT_NOCLUSTERW	| MNT_SUIDDIR	| MNT_SOFTDEP	| \
354 			MNT_IGNORE	| MNT_EXPUBLIC	| MNT_NOSYMFOLLOW | \
355 			MNT_GJOURNAL	| MNT_MULTILABEL | MNT_ACLS	| \
356 			MNT_NFS4ACLS	| MNT_AUTOMOUNTED | MNT_VERIFIED | \
357 			MNT_UNTRUSTED)
358 
359 /* Mask of flags that can be updated. */
360 #define	MNT_UPDATEMASK (MNT_NOSUID	| MNT_NOEXEC	| \
361 			MNT_SYNCHRONOUS	| MNT_UNION	| MNT_ASYNC	| \
362 			MNT_NOATIME | \
363 			MNT_NOSYMFOLLOW	| MNT_IGNORE	| \
364 			MNT_NOCLUSTERR	| MNT_NOCLUSTERW | MNT_SUIDDIR	| \
365 			MNT_ACLS	| MNT_USER	| MNT_NFS4ACLS	| \
366 			MNT_AUTOMOUNTED | MNT_UNTRUSTED)
367 
368 /*
369  * External filesystem command modifier flags.
370  * Unmount can use the MNT_FORCE flag.
371  * XXX: These are not STATES and really should be somewhere else.
372  * XXX: MNT_BYFSID and MNT_NONBUSY collide with MNT_ACLS and MNT_MULTILABEL,
373  *      but because MNT_ACLS and MNT_MULTILABEL are only used for mount(2),
374  *      and MNT_BYFSID and MNT_NONBUSY are only used for unmount(2),
375  *      it's harmless.
376  */
377 #define	MNT_UPDATE	0x0000000000010000ULL /* not real mount, just update */
378 #define	MNT_DELEXPORT	0x0000000000020000ULL /* delete export host lists */
379 #define	MNT_RELOAD	0x0000000000040000ULL /* reload filesystem data */
380 #define	MNT_FORCE	0x0000000000080000ULL /* force unmount or readonly */
381 #define	MNT_SNAPSHOT	0x0000000001000000ULL /* snapshot the filesystem */
382 #define	MNT_NONBUSY	0x0000000004000000ULL /* check vnode use counts. */
383 #define	MNT_BYFSID	0x0000000008000000ULL /* specify filesystem by ID. */
384 #define	MNT_NOCOVER	0x0000001000000000ULL /* Do not cover a mount point */
385 #define	MNT_EMPTYDIR	0x0000002000000000ULL /* Only mount on empty dir */
386 #define MNT_CMDFLAGS   (MNT_UPDATE	| MNT_DELEXPORT	| MNT_RELOAD	| \
387 			MNT_FORCE	| MNT_SNAPSHOT	| MNT_NONBUSY	| \
388 			MNT_BYFSID	| MNT_NOCOVER	| MNT_EMPTYDIR)
389 /*
390  * Internal filesystem control flags stored in mnt_kern_flag.
391  *
392  * MNTK_UNMOUNT locks the mount entry so that name lookup cannot
393  * proceed past the mount point.  This keeps the subtree stable during
394  * mounts and unmounts.  When non-forced unmount flushes all vnodes
395  * from the mp queue, the MNTK_UNMOUNT flag prevents insmntque() from
396  * queueing new vnodes.
397  *
398  * MNTK_UNMOUNTF permits filesystems to detect a forced unmount while
399  * dounmount() is still waiting to lock the mountpoint. This allows
400  * the filesystem to cancel operations that might otherwise deadlock
401  * with the unmount attempt (used by NFS).
402  */
403 #define MNTK_UNMOUNTF	0x00000001	/* forced unmount in progress */
404 #define MNTK_ASYNC	0x00000002	/* filtered async flag */
405 #define MNTK_SOFTDEP	0x00000004	/* async disabled by softdep */
406 #define MNTK_NOMSYNC	0x00000008	/* don't do msync */
407 #define	MNTK_DRAINING	0x00000010	/* lock draining is happening */
408 #define	MNTK_REFEXPIRE	0x00000020	/* refcount expiring is happening */
409 #define MNTK_EXTENDED_SHARED	0x00000040 /* Allow shared locking for more ops */
410 #define	MNTK_SHARED_WRITES	0x00000080 /* Allow shared locking for writes */
411 #define	MNTK_NO_IOPF	0x00000100	/* Disallow page faults during reads
412 					   and writes. Filesystem shall properly
413 					   handle i/o state on EFAULT. */
414 #define	MNTK_VGONE_UPPER	0x00000200
415 #define	MNTK_VGONE_WAITER	0x00000400
416 #define	MNTK_LOOKUP_EXCL_DOTDOT	0x00000800
417 #define	MNTK_MARKER		0x00001000
418 #define	MNTK_UNMAPPED_BUFS	0x00002000
419 #define	MNTK_USES_BCACHE	0x00004000 /* FS uses the buffer cache. */
420 #define	MNTK_TEXT_REFS		0x00008000 /* Keep use ref for text */
421 #define	MNTK_VMSETSIZE_BUG	0x00010000
422 #define	MNTK_UNIONFS	0x00020000	/* A hack for F_ISUNIONSTACK */
423 #define MNTK_NOASYNC	0x00800000	/* disable async */
424 #define MNTK_UNMOUNT	0x01000000	/* unmount in progress */
425 #define	MNTK_MWAIT	0x02000000	/* waiting for unmount to finish */
426 #define	MNTK_SUSPEND	0x08000000	/* request write suspension */
427 #define	MNTK_SUSPEND2	0x04000000	/* block secondary writes */
428 #define	MNTK_SUSPENDED	0x10000000	/* write operations are suspended */
429 #define	MNTK_NULL_NOCACHE	0x20000000 /* auto disable cache for nullfs
430 					      mounts over this fs */
431 #define MNTK_LOOKUP_SHARED	0x40000000 /* FS supports shared lock lookups */
432 #define	MNTK_NOKNOTE	0x80000000	/* Don't send KNOTEs from VOP hooks */
433 
434 #ifdef _KERNEL
435 static inline int
436 MNT_SHARED_WRITES(struct mount *mp)
437 {
438 
439 	return (mp != NULL && (mp->mnt_kern_flag & MNTK_SHARED_WRITES) != 0);
440 }
441 
442 static inline int
443 MNT_EXTENDED_SHARED(struct mount *mp)
444 {
445 
446 	return (mp != NULL && (mp->mnt_kern_flag & MNTK_EXTENDED_SHARED) != 0);
447 }
448 #endif
449 
450 /*
451  * Sysctl CTL_VFS definitions.
452  *
453  * Second level identifier specifies which filesystem. Second level
454  * identifier VFS_VFSCONF returns information about all filesystems.
455  * Second level identifier VFS_GENERIC is non-terminal.
456  */
457 #define	VFS_VFSCONF		0	/* get configured filesystems */
458 #define	VFS_GENERIC		0	/* generic filesystem information */
459 /*
460  * Third level identifiers for VFS_GENERIC are given below; third
461  * level identifiers for specific filesystems are given in their
462  * mount specific header files.
463  */
464 #define VFS_MAXTYPENUM	1	/* int: highest defined filesystem type */
465 #define VFS_CONF	2	/* struct: vfsconf for filesystem given
466 				   as next argument */
467 
468 /*
469  * Flags for various system call interfaces.
470  *
471  * waitfor flags to vfs_sync() and getfsstat()
472  */
473 #define MNT_WAIT	1	/* synchronously wait for I/O to complete */
474 #define MNT_NOWAIT	2	/* start all I/O, but do not wait for it */
475 #define MNT_LAZY	3	/* push data not written by filesystem syncer */
476 #define MNT_SUSPEND	4	/* Suspend file system after sync */
477 
478 /*
479  * Generic file handle
480  */
481 struct fhandle {
482 	fsid_t	fh_fsid;	/* Filesystem id of mount point */
483 	struct	fid fh_fid;	/* Filesys specific id */
484 };
485 typedef struct fhandle	fhandle_t;
486 
487 /*
488  * Old export arguments without security flavor list
489  */
490 struct oexport_args {
491 	int	ex_flags;		/* export related flags */
492 	uid_t	ex_root;		/* mapping for root uid */
493 	struct	xucred ex_anon;		/* mapping for anonymous user */
494 	struct	sockaddr *ex_addr;	/* net address to which exported */
495 	u_char	ex_addrlen;		/* and the net address length */
496 	struct	sockaddr *ex_mask;	/* mask of valid bits in saddr */
497 	u_char	ex_masklen;		/* and the smask length */
498 	char	*ex_indexfile;		/* index file for WebNFS URLs */
499 };
500 
501 /*
502  * Not quite so old export arguments with 32bit ex_flags and xucred ex_anon.
503  */
504 #define	MAXSECFLAVORS	5
505 struct o2export_args {
506 	int	ex_flags;		/* export related flags */
507 	uid_t	ex_root;		/* mapping for root uid */
508 	struct	xucred ex_anon;		/* mapping for anonymous user */
509 	struct	sockaddr *ex_addr;	/* net address to which exported */
510 	u_char	ex_addrlen;		/* and the net address length */
511 	struct	sockaddr *ex_mask;	/* mask of valid bits in saddr */
512 	u_char	ex_masklen;		/* and the smask length */
513 	char	*ex_indexfile;		/* index file for WebNFS URLs */
514 	int	ex_numsecflavors;	/* security flavor count */
515 	int	ex_secflavors[MAXSECFLAVORS]; /* list of security flavors */
516 };
517 
518 /*
519  * Export arguments for local filesystem mount calls.
520  */
521 struct export_args {
522 	uint64_t ex_flags;		/* export related flags */
523 	uid_t	ex_root;		/* mapping for root uid */
524 	uid_t	ex_uid;			/* mapping for anonymous user */
525 	int	ex_ngroups;
526 	gid_t	*ex_groups;
527 	struct	sockaddr *ex_addr;	/* net address to which exported */
528 	u_char	ex_addrlen;		/* and the net address length */
529 	struct	sockaddr *ex_mask;	/* mask of valid bits in saddr */
530 	u_char	ex_masklen;		/* and the smask length */
531 	char	*ex_indexfile;		/* index file for WebNFS URLs */
532 	int	ex_numsecflavors;	/* security flavor count */
533 	int	ex_secflavors[MAXSECFLAVORS]; /* list of security flavors */
534 };
535 
536 /*
537  * Structure holding information for a publicly exported filesystem
538  * (WebNFS). Currently the specs allow just for one such filesystem.
539  */
540 struct nfs_public {
541 	int		np_valid;	/* Do we hold valid information */
542 	fhandle_t	np_handle;	/* Filehandle for pub fs (internal) */
543 	struct mount	*np_mount;	/* Mountpoint of exported fs */
544 	char		*np_index;	/* Index file */
545 };
546 
547 /*
548  * Filesystem configuration information. One of these exists for each
549  * type of filesystem supported by the kernel. These are searched at
550  * mount time to identify the requested filesystem.
551  *
552  * XXX: Never change the first two arguments!
553  */
554 struct vfsconf {
555 	u_int	vfc_version;		/* ABI version number */
556 	char	vfc_name[MFSNAMELEN];	/* filesystem type name */
557 	struct	vfsops *vfc_vfsops;	/* filesystem operations vector */
558 	struct	vfsops *vfc_vfsops_sd;	/* ... signal-deferred */
559 	int	vfc_typenum;		/* historic filesystem type number */
560 	int	vfc_refcount;		/* number mounted of this type */
561 	int	vfc_flags;		/* permanent flags */
562 	int	vfc_prison_flag;	/* prison allow.mount.* flag */
563 	struct	vfsoptdecl *vfc_opts;	/* mount options */
564 	TAILQ_ENTRY(vfsconf) vfc_list;	/* list of vfscons */
565 };
566 
567 /* Userland version of the struct vfsconf. */
568 struct xvfsconf {
569 	struct	vfsops *vfc_vfsops;	/* filesystem operations vector */
570 	char	vfc_name[MFSNAMELEN];	/* filesystem type name */
571 	int	vfc_typenum;		/* historic filesystem type number */
572 	int	vfc_refcount;		/* number mounted of this type */
573 	int	vfc_flags;		/* permanent flags */
574 	struct	vfsconf *vfc_next;	/* next in list */
575 };
576 
577 #ifndef BURN_BRIDGES
578 struct ovfsconf {
579 	void	*vfc_vfsops;
580 	char	vfc_name[32];
581 	int	vfc_index;
582 	int	vfc_refcount;
583 	int	vfc_flags;
584 };
585 #endif
586 
587 /*
588  * NB: these flags refer to IMPLEMENTATION properties, not properties of
589  * any actual mounts; i.e., it does not make sense to change the flags.
590  */
591 #define	VFCF_STATIC	0x00010000	/* statically compiled into kernel */
592 #define	VFCF_NETWORK	0x00020000	/* may get data over the network */
593 #define	VFCF_READONLY	0x00040000	/* writes are not implemented */
594 #define	VFCF_SYNTHETIC	0x00080000	/* data does not represent real files */
595 #define	VFCF_LOOPBACK	0x00100000	/* aliases some other mounted FS */
596 #define	VFCF_UNICODE	0x00200000	/* stores file names as Unicode */
597 #define	VFCF_JAIL	0x00400000	/* can be mounted from within a jail */
598 #define	VFCF_DELEGADMIN	0x00800000	/* supports delegated administration */
599 #define	VFCF_SBDRY	0x01000000	/* Stop at Boundary: defer stop requests
600 					   to kernel->user (AST) transition */
601 
602 typedef uint32_t fsctlop_t;
603 
604 struct vfsidctl {
605 	int		vc_vers;	/* should be VFSIDCTL_VERS1 (below) */
606 	fsid_t		vc_fsid;	/* fsid to operate on */
607 	char		vc_fstypename[MFSNAMELEN];
608 					/* type of fs 'nfs' or '*' */
609 	fsctlop_t	vc_op;		/* operation VFS_CTL_* (below) */
610 	void		*vc_ptr;	/* pointer to data structure */
611 	size_t		vc_len;		/* sizeof said structure */
612 	u_int32_t	vc_spare[12];	/* spare (must be zero) */
613 };
614 
615 /* vfsidctl API version. */
616 #define VFS_CTL_VERS1	0x01
617 
618 /*
619  * New style VFS sysctls, do not reuse/conflict with the namespace for
620  * private sysctls.
621  * All "global" sysctl ops have the 33rd bit set:
622  * 0x...1....
623  * Private sysctl ops should have the 33rd bit unset.
624  */
625 #define VFS_CTL_QUERY	0x00010001	/* anything wrong? (vfsquery) */
626 #define VFS_CTL_TIMEO	0x00010002	/* set timeout for vfs notification */
627 #define VFS_CTL_NOLOCKS	0x00010003	/* disable file locking */
628 
629 struct vfsquery {
630 	u_int32_t	vq_flags;
631 	u_int32_t	vq_spare[31];
632 };
633 
634 /* vfsquery flags */
635 #define VQ_NOTRESP	0x0001	/* server down */
636 #define VQ_NEEDAUTH	0x0002	/* server bad auth */
637 #define VQ_LOWDISK	0x0004	/* we're low on space */
638 #define VQ_MOUNT	0x0008	/* new filesystem arrived */
639 #define VQ_UNMOUNT	0x0010	/* filesystem has left */
640 #define VQ_DEAD		0x0020	/* filesystem is dead, needs force unmount */
641 #define VQ_ASSIST	0x0040	/* filesystem needs assistance from external
642 				   program */
643 #define VQ_NOTRESPLOCK	0x0080	/* server lockd down */
644 #define VQ_FLAG0100	0x0100	/* placeholder */
645 #define VQ_FLAG0200	0x0200	/* placeholder */
646 #define VQ_FLAG0400	0x0400	/* placeholder */
647 #define VQ_FLAG0800	0x0800	/* placeholder */
648 #define VQ_FLAG1000	0x1000	/* placeholder */
649 #define VQ_FLAG2000	0x2000	/* placeholder */
650 #define VQ_FLAG4000	0x4000	/* placeholder */
651 #define VQ_FLAG8000	0x8000	/* placeholder */
652 
653 #ifdef _KERNEL
654 /* Point a sysctl request at a vfsidctl's data. */
655 #define VCTLTOREQ(vc, req)						\
656 	do {								\
657 		(req)->newptr = (vc)->vc_ptr;				\
658 		(req)->newlen = (vc)->vc_len;				\
659 		(req)->newidx = 0;					\
660 	} while (0)
661 #endif
662 
663 struct iovec;
664 struct uio;
665 
666 #ifdef _KERNEL
667 
668 /*
669  * vfs_busy specific flags and mask.
670  */
671 #define	MBF_NOWAIT	0x01
672 #define	MBF_MNTLSTLOCK	0x02
673 #define	MBF_MASK	(MBF_NOWAIT | MBF_MNTLSTLOCK)
674 
675 #ifdef MALLOC_DECLARE
676 MALLOC_DECLARE(M_MOUNT);
677 MALLOC_DECLARE(M_STATFS);
678 #endif
679 extern int maxvfsconf;		/* highest defined filesystem type */
680 
681 TAILQ_HEAD(vfsconfhead, vfsconf);
682 extern struct vfsconfhead vfsconf;
683 
684 /*
685  * Operations supported on mounted filesystem.
686  */
687 struct mount_args;
688 struct nameidata;
689 struct sysctl_req;
690 struct mntarg;
691 
692 /*
693  * N.B., vfs_cmount is the ancient vfsop invoked by the old mount(2) syscall.
694  * The new way is vfs_mount.
695  *
696  * vfs_cmount implementations typically translate arguments from their
697  * respective old per-FS structures into the key-value list supported by
698  * nmount(2), then use kernel_mount(9) to mimic nmount(2) from kernelspace.
699  *
700  * Filesystems with mounters that use nmount(2) do not need to and should not
701  * implement vfs_cmount.  Hopefully a future cleanup can remove vfs_cmount and
702  * mount(2) entirely.
703  */
704 typedef int vfs_cmount_t(struct mntarg *ma, void *data, uint64_t flags);
705 typedef int vfs_unmount_t(struct mount *mp, int mntflags);
706 typedef int vfs_root_t(struct mount *mp, int flags, struct vnode **vpp);
707 typedef	int vfs_quotactl_t(struct mount *mp, int cmds, uid_t uid, void *arg);
708 typedef	int vfs_statfs_t(struct mount *mp, struct statfs *sbp);
709 typedef	int vfs_sync_t(struct mount *mp, int waitfor);
710 typedef	int vfs_vget_t(struct mount *mp, ino_t ino, int flags,
711 		    struct vnode **vpp);
712 typedef	int vfs_fhtovp_t(struct mount *mp, struct fid *fhp,
713 		    int flags, struct vnode **vpp);
714 typedef	int vfs_checkexp_t(struct mount *mp, struct sockaddr *nam,
715 		    uint64_t *extflagsp, struct ucred **credanonp,
716 		    int *numsecflavors, int *secflavors);
717 typedef	int vfs_init_t(struct vfsconf *);
718 typedef	int vfs_uninit_t(struct vfsconf *);
719 typedef	int vfs_extattrctl_t(struct mount *mp, int cmd,
720 		    struct vnode *filename_vp, int attrnamespace,
721 		    const char *attrname);
722 typedef	int vfs_mount_t(struct mount *mp);
723 typedef int vfs_sysctl_t(struct mount *mp, fsctlop_t op,
724 		    struct sysctl_req *req);
725 typedef void vfs_susp_clean_t(struct mount *mp);
726 typedef void vfs_notify_lowervp_t(struct mount *mp, struct vnode *lowervp);
727 typedef void vfs_purge_t(struct mount *mp);
728 
729 struct vfsops {
730 	vfs_mount_t		*vfs_mount;
731 	vfs_cmount_t		*vfs_cmount;
732 	vfs_unmount_t		*vfs_unmount;
733 	vfs_root_t		*vfs_root;
734 	vfs_root_t		*vfs_cachedroot;
735 	vfs_quotactl_t		*vfs_quotactl;
736 	vfs_statfs_t		*vfs_statfs;
737 	vfs_sync_t		*vfs_sync;
738 	vfs_vget_t		*vfs_vget;
739 	vfs_fhtovp_t		*vfs_fhtovp;
740 	vfs_checkexp_t		*vfs_checkexp;
741 	vfs_init_t		*vfs_init;
742 	vfs_uninit_t		*vfs_uninit;
743 	vfs_extattrctl_t	*vfs_extattrctl;
744 	vfs_sysctl_t		*vfs_sysctl;
745 	vfs_susp_clean_t	*vfs_susp_clean;
746 	vfs_notify_lowervp_t	*vfs_reclaim_lowervp;
747 	vfs_notify_lowervp_t	*vfs_unlink_lowervp;
748 	vfs_purge_t		*vfs_purge;
749 	vfs_mount_t		*vfs_spare[6];	/* spares for ABI compat */
750 };
751 
752 vfs_statfs_t	__vfs_statfs;
753 
754 #define	VFS_MOUNT(MP) ({						\
755 	int _rc;							\
756 									\
757 	TSRAW(curthread, TS_ENTER, "VFS_MOUNT", (MP)->mnt_vfc->vfc_name);\
758 	_rc = (*(MP)->mnt_op->vfs_mount)(MP);				\
759 	TSRAW(curthread, TS_EXIT, "VFS_MOUNT", (MP)->mnt_vfc->vfc_name);\
760 	_rc; })
761 
762 #define	VFS_UNMOUNT(MP, FORCE) ({					\
763 	int _rc;							\
764 									\
765 	_rc = (*(MP)->mnt_op->vfs_unmount)(MP, FORCE);			\
766 	_rc; })
767 
768 #define	VFS_ROOT(MP, FLAGS, VPP) ({					\
769 	int _rc;							\
770 									\
771 	_rc = (*(MP)->mnt_op->vfs_root)(MP, FLAGS, VPP);		\
772 	_rc; })
773 
774 #define	VFS_CACHEDROOT(MP, FLAGS, VPP) ({				\
775 	int _rc;							\
776 									\
777 	_rc = (*(MP)->mnt_op->vfs_cachedroot)(MP, FLAGS, VPP);		\
778 	_rc; })
779 
780 #define	VFS_QUOTACTL(MP, C, U, A) ({					\
781 	int _rc;							\
782 									\
783 	_rc = (*(MP)->mnt_op->vfs_quotactl)(MP, C, U, A);		\
784 	_rc; })
785 
786 #define	VFS_STATFS(MP, SBP) ({						\
787 	int _rc;							\
788 									\
789 	_rc = __vfs_statfs((MP), (SBP));				\
790 	_rc; })
791 
792 #define	VFS_SYNC(MP, WAIT) ({						\
793 	int _rc;							\
794 									\
795 	_rc = (*(MP)->mnt_op->vfs_sync)(MP, WAIT);			\
796 	_rc; })
797 
798 #define	VFS_VGET(MP, INO, FLAGS, VPP) ({				\
799 	int _rc;							\
800 									\
801 	_rc = (*(MP)->mnt_op->vfs_vget)(MP, INO, FLAGS, VPP);		\
802 	_rc; })
803 
804 #define	VFS_FHTOVP(MP, FIDP, FLAGS, VPP) ({				\
805 	int _rc;							\
806 									\
807 	_rc = (*(MP)->mnt_op->vfs_fhtovp)(MP, FIDP, FLAGS, VPP);	\
808 	_rc; })
809 
810 #define	VFS_CHECKEXP(MP, NAM, EXFLG, CRED, NUMSEC, SEC) ({		\
811 	int _rc;							\
812 									\
813 	_rc = (*(MP)->mnt_op->vfs_checkexp)(MP, NAM, EXFLG, CRED, NUMSEC,\
814 	    SEC);							\
815 	_rc; })
816 
817 #define	VFS_EXTATTRCTL(MP, C, FN, NS, N) ({				\
818 	int _rc;							\
819 									\
820 	_rc = (*(MP)->mnt_op->vfs_extattrctl)(MP, C, FN, NS, N);	\
821 	_rc; })
822 
823 #define	VFS_SYSCTL(MP, OP, REQ) ({					\
824 	int _rc;							\
825 									\
826 	_rc = (*(MP)->mnt_op->vfs_sysctl)(MP, OP, REQ);			\
827 	_rc; })
828 
829 #define	VFS_SUSP_CLEAN(MP) do {						\
830 	if (*(MP)->mnt_op->vfs_susp_clean != NULL) {			\
831 		(*(MP)->mnt_op->vfs_susp_clean)(MP);			\
832 	}								\
833 } while (0)
834 
835 #define	VFS_RECLAIM_LOWERVP(MP, VP) do {				\
836 	if (*(MP)->mnt_op->vfs_reclaim_lowervp != NULL) {		\
837 		(*(MP)->mnt_op->vfs_reclaim_lowervp)((MP), (VP));	\
838 	}								\
839 } while (0)
840 
841 #define	VFS_UNLINK_LOWERVP(MP, VP) do {					\
842 	if (*(MP)->mnt_op->vfs_unlink_lowervp != NULL) {		\
843 		(*(MP)->mnt_op->vfs_unlink_lowervp)((MP), (VP));	\
844 	}								\
845 } while (0)
846 
847 #define	VFS_PURGE(MP) do {						\
848 	if (*(MP)->mnt_op->vfs_purge != NULL) {				\
849 		(*(MP)->mnt_op->vfs_purge)(MP);				\
850 	}								\
851 } while (0)
852 
853 #define VFS_KNOTE_LOCKED(vp, hint) do					\
854 {									\
855 	if (((vp)->v_vflag & VV_NOKNOTE) == 0)				\
856 		VN_KNOTE((vp), (hint), KNF_LISTLOCKED);			\
857 } while (0)
858 
859 #define VFS_KNOTE_UNLOCKED(vp, hint) do					\
860 {									\
861 	if (((vp)->v_vflag & VV_NOKNOTE) == 0)				\
862 		VN_KNOTE((vp), (hint), 0);				\
863 } while (0)
864 
865 #define	VFS_NOTIFY_UPPER_RECLAIM	1
866 #define	VFS_NOTIFY_UPPER_UNLINK		2
867 
868 #include <sys/module.h>
869 
870 /*
871  * Version numbers.
872  */
873 #define VFS_VERSION_00	0x19660120
874 #define VFS_VERSION_01	0x20121030
875 #define VFS_VERSION_02	0x20180504
876 #define VFS_VERSION	VFS_VERSION_02
877 
878 #define VFS_SET(vfsops, fsname, flags) \
879 	static struct vfsconf fsname ## _vfsconf = {		\
880 		.vfc_version = VFS_VERSION,			\
881 		.vfc_name = #fsname,				\
882 		.vfc_vfsops = &vfsops,				\
883 		.vfc_typenum = -1,				\
884 		.vfc_flags = flags,				\
885 	};							\
886 	static moduledata_t fsname ## _mod = {			\
887 		#fsname,					\
888 		vfs_modevent,					\
889 		& fsname ## _vfsconf				\
890 	};							\
891 	DECLARE_MODULE(fsname, fsname ## _mod, SI_SUB_VFS, SI_ORDER_MIDDLE)
892 
893 /*
894  * exported vnode operations
895  */
896 
897 int	dounmount(struct mount *, int, struct thread *);
898 
899 int	kernel_mount(struct mntarg *ma, uint64_t flags);
900 int	kernel_vmount(int flags, ...);
901 struct mntarg *mount_arg(struct mntarg *ma, const char *name, const void *val, int len);
902 struct mntarg *mount_argb(struct mntarg *ma, int flag, const char *name);
903 struct mntarg *mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...);
904 struct mntarg *mount_argsu(struct mntarg *ma, const char *name, const void *val, int len);
905 void	statfs_scale_blocks(struct statfs *sf, long max_size);
906 struct vfsconf *vfs_byname(const char *);
907 struct vfsconf *vfs_byname_kld(const char *, struct thread *td, int *);
908 void	vfs_mount_destroy(struct mount *);
909 void	vfs_event_signal(fsid_t *, u_int32_t, intptr_t);
910 void	vfs_freeopts(struct vfsoptlist *opts);
911 void	vfs_deleteopt(struct vfsoptlist *opts, const char *name);
912 int	vfs_buildopts(struct uio *auio, struct vfsoptlist **options);
913 int	vfs_flagopt(struct vfsoptlist *opts, const char *name, uint64_t *w,
914 	    uint64_t val);
915 int	vfs_getopt(struct vfsoptlist *, const char *, void **, int *);
916 int	vfs_getopt_pos(struct vfsoptlist *opts, const char *name);
917 int	vfs_getopt_size(struct vfsoptlist *opts, const char *name,
918 	    off_t *value);
919 char	*vfs_getopts(struct vfsoptlist *, const char *, int *error);
920 int	vfs_copyopt(struct vfsoptlist *, const char *, void *, int);
921 int	vfs_filteropt(struct vfsoptlist *, const char **legal);
922 void	vfs_opterror(struct vfsoptlist *opts, const char *fmt, ...);
923 int	vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...);
924 int	vfs_setopt(struct vfsoptlist *opts, const char *name, void *value,
925 	    int len);
926 int	vfs_setopt_part(struct vfsoptlist *opts, const char *name, void *value,
927 	    int len);
928 int	vfs_setopts(struct vfsoptlist *opts, const char *name,
929 	    const char *value);
930 int	vfs_setpublicfs			    /* set publicly exported fs */
931 	    (struct mount *, struct netexport *, struct export_args *);
932 void	vfs_periodic(struct mount *, int);
933 int	vfs_busy(struct mount *, int);
934 int	vfs_export			 /* process mount export info */
935 	    (struct mount *, struct export_args *);
936 void	vfs_allocate_syncvnode(struct mount *);
937 void	vfs_deallocate_syncvnode(struct mount *);
938 int	vfs_donmount(struct thread *td, uint64_t fsflags,
939 	    struct uio *fsoptions);
940 void	vfs_getnewfsid(struct mount *);
941 struct cdev *vfs_getrootfsid(struct mount *);
942 struct	mount *vfs_getvfs(fsid_t *);      /* return vfs given fsid */
943 struct	mount *vfs_busyfs(fsid_t *);
944 int	vfs_modevent(module_t, int, void *);
945 void	vfs_mount_error(struct mount *, const char *, ...);
946 void	vfs_mountroot(void);			/* mount our root filesystem */
947 void	vfs_mountedfrom(struct mount *, const char *from);
948 void	vfs_notify_upper(struct vnode *, int);
949 void	vfs_ref(struct mount *);
950 void	vfs_rel(struct mount *);
951 struct mount *vfs_mount_alloc(struct vnode *, struct vfsconf *, const char *,
952 	    struct ucred *);
953 int	vfs_suser(struct mount *, struct thread *);
954 void	vfs_unbusy(struct mount *);
955 void	vfs_unmountall(void);
956 extern	TAILQ_HEAD(mntlist, mount) mountlist;	/* mounted filesystem list */
957 extern	struct mtx mountlist_mtx;
958 extern	struct nfs_public nfs_pub;
959 extern	struct sx vfsconf_sx;
960 #define	vfsconf_lock()		sx_xlock(&vfsconf_sx)
961 #define	vfsconf_unlock()	sx_xunlock(&vfsconf_sx)
962 #define	vfsconf_slock()		sx_slock(&vfsconf_sx)
963 #define	vfsconf_sunlock()	sx_sunlock(&vfsconf_sx)
964 struct vnode *mntfs_allocvp(struct mount *, struct vnode *);
965 void   mntfs_freevp(struct vnode *);
966 
967 /*
968  * Declarations for these vfs default operations are located in
969  * kern/vfs_default.c.  They will be automatically used to replace
970  * null entries in VFS ops tables when registering a new filesystem
971  * type in the global table.
972  */
973 vfs_root_t		vfs_stdroot;
974 vfs_quotactl_t		vfs_stdquotactl;
975 vfs_statfs_t		vfs_stdstatfs;
976 vfs_sync_t		vfs_stdsync;
977 vfs_sync_t		vfs_stdnosync;
978 vfs_vget_t		vfs_stdvget;
979 vfs_fhtovp_t		vfs_stdfhtovp;
980 vfs_checkexp_t		vfs_stdcheckexp;
981 vfs_init_t		vfs_stdinit;
982 vfs_uninit_t		vfs_stduninit;
983 vfs_extattrctl_t	vfs_stdextattrctl;
984 vfs_sysctl_t		vfs_stdsysctl;
985 
986 void	syncer_suspend(void);
987 void	syncer_resume(void);
988 
989 struct vnode *vfs_cache_root_clear(struct mount *);
990 void	vfs_cache_root_set(struct mount *, struct vnode *);
991 
992 void	vfs_op_barrier_wait(struct mount *);
993 void	vfs_op_enter(struct mount *);
994 void	vfs_op_exit_locked(struct mount *);
995 void	vfs_op_exit(struct mount *);
996 
997 #ifdef DIAGNOSTIC
998 void	vfs_assert_mount_counters(struct mount *);
999 void	vfs_dump_mount_counters(struct mount *);
1000 #else
1001 #define vfs_assert_mount_counters(mp) do { } while (0)
1002 #define vfs_dump_mount_counters(mp) do { } while (0)
1003 #endif
1004 
1005 enum mount_counter { MNT_COUNT_REF, MNT_COUNT_LOCKREF, MNT_COUNT_WRITEOPCOUNT };
1006 int	vfs_mount_fetch_counter(struct mount *, enum mount_counter);
1007 
1008 /*
1009  * Code transitioning mnt_vfs_ops to > 0 issues IPIs until it observes
1010  * all CPUs not executing code enclosed by mnt_thread_in_ops_pcpu.
1011  *
1012  * This provides an invariant that by the time the last CPU is observed not
1013  * executing, everyone else entering will see the counter > 0 and exit.
1014  *
1015  * Note there is no barrier between vfs_ops and the rest of the code in the
1016  * section. It is not necessary as the writer has to wait for everyone to drain
1017  * before making any changes or only make changes safe while the section is
1018  * executed.
1019  */
1020 #define vfs_op_thread_entered(mp) ({				\
1021 	MPASS(curthread->td_critnest > 0);			\
1022 	*zpcpu_get(mp->mnt_thread_in_ops_pcpu) == 1;		\
1023 })
1024 
1025 #define vfs_op_thread_enter(mp) ({				\
1026 	bool _retval = true;					\
1027 	critical_enter();					\
1028 	MPASS(!vfs_op_thread_entered(mp));			\
1029 	zpcpu_set_protected(mp->mnt_thread_in_ops_pcpu, 1);	\
1030 	__compiler_membar();					\
1031 	if (__predict_false(mp->mnt_vfs_ops > 0)) {		\
1032 		vfs_op_thread_exit(mp);				\
1033 		_retval = false;				\
1034 	}							\
1035 	_retval;						\
1036 })
1037 
1038 #define vfs_op_thread_exit(mp) do {				\
1039 	MPASS(vfs_op_thread_entered(mp));			\
1040 	__compiler_membar();					\
1041 	zpcpu_set_protected(mp->mnt_thread_in_ops_pcpu, 0);	\
1042 	critical_exit();					\
1043 } while (0)
1044 
1045 #define vfs_mp_count_add_pcpu(mp, count, val) do {		\
1046 	MPASS(vfs_op_thread_entered(mp));			\
1047 	zpcpu_add_protected(mp->mnt_##count##_pcpu, val);	\
1048 } while (0)
1049 
1050 #define vfs_mp_count_sub_pcpu(mp, count, val) do {		\
1051 	MPASS(vfs_op_thread_entered(mp));			\
1052 	zpcpu_sub_protected(mp->mnt_##count##_pcpu, val);	\
1053 } while (0)
1054 
1055 #else /* !_KERNEL */
1056 
1057 #include <sys/cdefs.h>
1058 
1059 struct stat;
1060 
1061 __BEGIN_DECLS
1062 int	fhlink(struct fhandle *, const char *);
1063 int	fhlinkat(struct fhandle *, int, const char *);
1064 int	fhopen(const struct fhandle *, int);
1065 int	fhreadlink(struct fhandle *, char *, size_t);
1066 int	fhstat(const struct fhandle *, struct stat *);
1067 int	fhstatfs(const struct fhandle *, struct statfs *);
1068 int	fstatfs(int, struct statfs *);
1069 int	getfh(const char *, fhandle_t *);
1070 int	getfhat(int, char *, struct fhandle *, int);
1071 int	getfsstat(struct statfs *, long, int);
1072 int	getmntinfo(struct statfs **, int);
1073 int	lgetfh(const char *, fhandle_t *);
1074 int	mount(const char *, const char *, int, void *);
1075 int	nmount(struct iovec *, unsigned int, int);
1076 int	statfs(const char *, struct statfs *);
1077 int	unmount(const char *, int);
1078 
1079 /* C library stuff */
1080 int	getvfsbyname(const char *, struct xvfsconf *);
1081 __END_DECLS
1082 
1083 #endif /* _KERNEL */
1084 
1085 #endif /* !_SYS_MOUNT_H_ */
1086