xref: /freebsd/sys/sys/mount.h (revision 1f1e2261)
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/types.h>
42 #include <sys/lock.h>
43 #include <sys/lockmgr.h>
44 #include <sys/tslog.h>
45 #include <sys/_mutex.h>
46 #include <sys/_sx.h>
47 #endif
48 
49 /*
50  * NOTE: When changing statfs structure, mount structure, MNT_* flags or
51  * MNTK_* flags also update DDB show mount command in vfs_subr.c.
52  */
53 
54 typedef struct fsid { int32_t val[2]; } fsid_t;	/* filesystem id type */
55 
56 #define fsidcmp(a, b) memcmp((a), (b), sizeof(fsid_t))
57 
58 /*
59  * File identifier.
60  * These are unique per filesystem on a single machine.
61  *
62  * Note that the offset of fid_data is 4 bytes, so care must be taken to avoid
63  * undefined behavior accessing unaligned fields within an embedded struct.
64  */
65 #define	MAXFIDSZ	16
66 
67 struct fid {
68 	u_short		fid_len;		/* length of data in bytes */
69 	u_short		fid_data0;		/* force longword alignment */
70 	char		fid_data[MAXFIDSZ];	/* data (variable length) */
71 };
72 
73 /*
74  * filesystem statistics
75  */
76 #define	MFSNAMELEN	16		/* length of type name including null */
77 #define	MNAMELEN	1024		/* size of on/from name bufs */
78 #define	STATFS_VERSION	0x20140518	/* current version number */
79 struct statfs {
80 	uint32_t f_version;		/* structure version number */
81 	uint32_t f_type;		/* type of filesystem */
82 	uint64_t f_flags;		/* copy of mount exported flags */
83 	uint64_t f_bsize;		/* filesystem fragment size */
84 	uint64_t f_iosize;		/* optimal transfer block size */
85 	uint64_t f_blocks;		/* total data blocks in filesystem */
86 	uint64_t f_bfree;		/* free blocks in filesystem */
87 	int64_t	 f_bavail;		/* free blocks avail to non-superuser */
88 	uint64_t f_files;		/* total file nodes in filesystem */
89 	int64_t	 f_ffree;		/* free nodes avail to non-superuser */
90 	uint64_t f_syncwrites;		/* count of sync writes since mount */
91 	uint64_t f_asyncwrites;		/* count of async writes since mount */
92 	uint64_t f_syncreads;		/* count of sync reads since mount */
93 	uint64_t f_asyncreads;		/* count of async reads since mount */
94 	uint32_t f_nvnodelistsize;	/* # of vnodes */
95 	uint32_t f_spare0;		/* unused spare */
96 	uint64_t f_spare[9];		/* unused spare */
97 	uint32_t f_namemax;		/* maximum filename length */
98 	uid_t	  f_owner;		/* user that mounted the filesystem */
99 	fsid_t	  f_fsid;		/* filesystem id */
100 	char	  f_charspare[80];	    /* spare string space */
101 	char	  f_fstypename[MFSNAMELEN]; /* filesystem type name */
102 	char	  f_mntfromname[MNAMELEN];  /* mounted filesystem */
103 	char	  f_mntonname[MNAMELEN];    /* directory on which mounted */
104 };
105 
106 #if defined(_WANT_FREEBSD11_STATFS) || defined(_KERNEL)
107 #define	FREEBSD11_STATFS_VERSION	0x20030518 /* current version number */
108 struct freebsd11_statfs {
109 	uint32_t f_version;		/* structure version number */
110 	uint32_t f_type;		/* type of filesystem */
111 	uint64_t f_flags;		/* copy of mount exported flags */
112 	uint64_t f_bsize;		/* filesystem fragment size */
113 	uint64_t f_iosize;		/* optimal transfer block size */
114 	uint64_t f_blocks;		/* total data blocks in filesystem */
115 	uint64_t f_bfree;		/* free blocks in filesystem */
116 	int64_t	 f_bavail;		/* free blocks avail to non-superuser */
117 	uint64_t f_files;		/* total file nodes in filesystem */
118 	int64_t	 f_ffree;		/* free nodes avail to non-superuser */
119 	uint64_t f_syncwrites;		/* count of sync writes since mount */
120 	uint64_t f_asyncwrites;		/* count of async writes since mount */
121 	uint64_t f_syncreads;		/* count of sync reads since mount */
122 	uint64_t f_asyncreads;		/* count of async reads since mount */
123 	uint64_t f_spare[10];		/* unused spare */
124 	uint32_t f_namemax;		/* maximum filename length */
125 	uid_t	  f_owner;		/* user that mounted the filesystem */
126 	fsid_t	  f_fsid;		/* filesystem id */
127 	char	  f_charspare[80];	/* spare string space */
128 	char	  f_fstypename[16];	/* filesystem type name */
129 	char	  f_mntfromname[88];	/* mounted filesystem */
130 	char	  f_mntonname[88];	/* directory on which mounted */
131 };
132 #endif /* _WANT_FREEBSD11_STATFS || _KERNEL */
133 
134 #ifdef _KERNEL
135 #define	OMFSNAMELEN	16	/* length of fs type name, including null */
136 #define	OMNAMELEN	(88 - 2 * sizeof(long))	/* size of on/from name bufs */
137 
138 /* XXX getfsstat.2 is out of date with write and read counter changes here. */
139 /* XXX statfs.2 is out of date with read counter changes here. */
140 struct ostatfs {
141 	long	f_spare2;		/* placeholder */
142 	long	f_bsize;		/* fundamental filesystem block size */
143 	long	f_iosize;		/* optimal transfer block size */
144 	long	f_blocks;		/* total data blocks in filesystem */
145 	long	f_bfree;		/* free blocks in fs */
146 	long	f_bavail;		/* free blocks avail to non-superuser */
147 	long	f_files;		/* total file nodes in filesystem */
148 	long	f_ffree;		/* free file nodes in fs */
149 	fsid_t	f_fsid;			/* filesystem id */
150 	uid_t	f_owner;		/* user that mounted the filesystem */
151 	int	f_type;			/* type of filesystem */
152 	int	f_flags;		/* copy of mount exported flags */
153 	long	f_syncwrites;		/* count of sync writes since mount */
154 	long	f_asyncwrites;		/* count of async writes since mount */
155 	char	f_fstypename[OMFSNAMELEN]; /* fs type name */
156 	char	f_mntonname[OMNAMELEN];	/* directory on which mounted */
157 	long	f_syncreads;		/* count of sync reads since mount */
158 	long	f_asyncreads;		/* count of async reads since mount */
159 	short	f_spares1;		/* unused spare */
160 	char	f_mntfromname[OMNAMELEN];/* mounted filesystem */
161 	short	f_spares2;		/* unused spare */
162 	/*
163 	 * XXX on machines where longs are aligned to 8-byte boundaries, there
164 	 * is an unnamed int32_t here.  This spare was after the apparent end
165 	 * of the struct until we bit off the read counters from f_mntonname.
166 	 */
167 	long	f_spare[2];		/* unused spare */
168 };
169 #endif	/* _KERNEL */
170 
171 #if defined(_WANT_MOUNT) || defined(_KERNEL)
172 TAILQ_HEAD(vnodelst, vnode);
173 
174 /* Mount options list */
175 TAILQ_HEAD(vfsoptlist, vfsopt);
176 struct vfsopt {
177 	TAILQ_ENTRY(vfsopt) link;
178 	char	*name;
179 	void	*value;
180 	int	len;
181 	int	pos;
182 	int	seen;
183 };
184 
185 struct mount_pcpu {
186 	int		mntp_thread_in_ops;
187 	int		mntp_ref;
188 	int		mntp_lockref;
189 	int		mntp_writeopcount;
190 };
191 
192 _Static_assert(sizeof(struct mount_pcpu) == 16,
193     "the struct is allocated from pcpu 16 zone");
194 
195 /*
196  * Structure for tracking a stacked filesystem mounted above another
197  * filesystem.  This is expected to be stored in the upper FS' per-mount data.
198  *
199  * Lock reference:
200  *	i - lower mount interlock
201  *	c - constant from node initialization
202  */
203 struct mount_upper_node {
204 	struct mount 	*mp;	/* (c) mount object for upper FS */
205 	TAILQ_ENTRY(mount_upper_node) mnt_upper_link;	/* (i) position in uppers list */
206 };
207 
208 /*
209  * Structure per mounted filesystem.  Each mounted filesystem has an
210  * array of operations and an instance record.  The filesystems are
211  * put on a doubly linked list.
212  *
213  * Lock reference:
214  * 	l - mnt_listmtx
215  *	m - mountlist_mtx
216  *	i - interlock
217  *	v - vnode freelist mutex
218  *	d - deferred unmount list mutex
219  *
220  * Unmarked fields are considered stable as long as a ref is held.
221  *
222  */
223 struct mount {
224 	int 		mnt_vfs_ops;		/* (i) pending vfs ops */
225 	int		mnt_kern_flag;		/* (i) kernel only flags */
226 	uint64_t	mnt_flag;		/* (i) flags shared with user */
227 	struct mount_pcpu *mnt_pcpu;		/* per-CPU data */
228 	struct vnode	*mnt_rootvnode;
229 	struct vnode	*mnt_vnodecovered;	/* vnode we mounted on */
230 	struct vfsops	*mnt_op;		/* operations on fs */
231 	struct vfsconf	*mnt_vfc;		/* configuration info */
232 	struct mtx __aligned(CACHE_LINE_SIZE)	mnt_mtx; /* mount structure interlock */
233 	int		mnt_gen;		/* struct mount generation */
234 #define	mnt_startzero	mnt_list
235 	TAILQ_ENTRY(mount) mnt_list;		/* (m) mount list */
236 	struct vnode	*mnt_syncer;		/* syncer vnode */
237 	int		mnt_ref;		/* (i) Reference count */
238 	struct vnodelst	mnt_nvnodelist;		/* (i) list of vnodes */
239 	int		mnt_nvnodelistsize;	/* (i) # of vnodes */
240 	int		mnt_writeopcount;	/* (i) write syscalls pending */
241 	struct vfsoptlist *mnt_opt;		/* current mount options */
242 	struct vfsoptlist *mnt_optnew;		/* new options passed to fs */
243 	struct statfs	mnt_stat;		/* cache of filesystem stats */
244 	struct ucred	*mnt_cred;		/* credentials of mounter */
245 	void *		mnt_data;		/* private data */
246 	time_t		mnt_time;		/* last time written*/
247 	int		mnt_iosize_max;		/* max size for clusters, etc */
248 	struct netexport *mnt_export;		/* export list */
249 	struct label	*mnt_label;		/* MAC label for the fs */
250 	u_int		mnt_hashseed;		/* Random seed for vfs_hash */
251 	int		mnt_lockref;		/* (i) Lock reference count */
252 	int		mnt_secondary_writes;   /* (i) # of secondary writes */
253 	int		mnt_secondary_accwrites;/* (i) secondary wr. starts */
254 	struct thread	*mnt_susp_owner;	/* (i) thread owning suspension */
255 #define	mnt_endzero	mnt_gjprovider
256 	char		*mnt_gjprovider;	/* gjournal provider name */
257 	struct mtx	mnt_listmtx;
258 	struct vnodelst	mnt_lazyvnodelist;	/* (l) list of lazy vnodes */
259 	int		mnt_lazyvnodelistsize;	/* (l) # of lazy vnodes */
260 	int		mnt_upper_pending;	/* (i) # of pending ops on mnt_uppers */
261 	struct lock	mnt_explock;		/* vfs_export walkers lock */
262 	TAILQ_HEAD(, mount_upper_node) mnt_uppers; /* (i) upper mounts over us */
263 	TAILQ_HEAD(, mount_upper_node) mnt_notify; /* (i) upper mounts for notification */
264 	STAILQ_ENTRY(mount) mnt_taskqueue_link;	/* (d) our place in deferred unmount list */
265 	uint64_t	mnt_taskqueue_flags;	/* (d) unmount flags passed from taskqueue */
266 	unsigned int	mnt_unmount_retries;	/* (d) # of failed deferred unmount attempts */
267 };
268 #endif	/* _WANT_MOUNT || _KERNEL */
269 
270 #ifdef _KERNEL
271 /*
272  * Definitions for MNT_VNODE_FOREACH_ALL.
273  */
274 struct vnode *__mnt_vnode_next_all(struct vnode **mvp, struct mount *mp);
275 struct vnode *__mnt_vnode_first_all(struct vnode **mvp, struct mount *mp);
276 void          __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp);
277 
278 #define MNT_VNODE_FOREACH_ALL(vp, mp, mvp)				\
279 	for (vp = __mnt_vnode_first_all(&(mvp), (mp));			\
280 		(vp) != NULL; vp = __mnt_vnode_next_all(&(mvp), (mp)))
281 
282 #define MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp)				\
283 	do {								\
284 		MNT_ILOCK(mp);						\
285 		__mnt_vnode_markerfree_all(&(mvp), (mp));		\
286 		/* MNT_IUNLOCK(mp); -- done in above function */	\
287 		mtx_assert(MNT_MTX(mp), MA_NOTOWNED);			\
288 	} while (0)
289 
290 /*
291  * Definitions for MNT_VNODE_FOREACH_LAZY.
292  */
293 typedef int mnt_lazy_cb_t(struct vnode *, void *);
294 struct vnode *__mnt_vnode_next_lazy(struct vnode **mvp, struct mount *mp,
295     mnt_lazy_cb_t *cb, void *cbarg);
296 struct vnode *__mnt_vnode_first_lazy(struct vnode **mvp, struct mount *mp,
297     mnt_lazy_cb_t *cb, void *cbarg);
298 void          __mnt_vnode_markerfree_lazy(struct vnode **mvp, struct mount *mp);
299 
300 #define MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, cb, cbarg)			\
301 	for (vp = __mnt_vnode_first_lazy(&(mvp), (mp), (cb), (cbarg));	\
302 		(vp) != NULL; 						\
303 		vp = __mnt_vnode_next_lazy(&(mvp), (mp), (cb), (cbarg)))
304 
305 #define MNT_VNODE_FOREACH_LAZY_ABORT(mp, mvp)				\
306 	__mnt_vnode_markerfree_lazy(&(mvp), (mp))
307 
308 #define	MNT_ILOCK(mp)	mtx_lock(&(mp)->mnt_mtx)
309 #define	MNT_ITRYLOCK(mp) mtx_trylock(&(mp)->mnt_mtx)
310 #define	MNT_IUNLOCK(mp)	mtx_unlock(&(mp)->mnt_mtx)
311 #define	MNT_MTX(mp)	(&(mp)->mnt_mtx)
312 
313 #define	MNT_REF(mp)	do {						\
314 	mtx_assert(MNT_MTX(mp), MA_OWNED);				\
315 	mp->mnt_ref++;							\
316 } while (0)
317 #define	MNT_REL(mp)	do {						\
318 	mtx_assert(MNT_MTX(mp), MA_OWNED);				\
319 	(mp)->mnt_ref--;						\
320 	if ((mp)->mnt_vfs_ops && (mp)->mnt_ref < 0)		\
321 		vfs_dump_mount_counters(mp);				\
322 	if ((mp)->mnt_ref == 0 && (mp)->mnt_vfs_ops)		\
323 		wakeup((mp));						\
324 } while (0)
325 
326 #endif /* _KERNEL */
327 
328 #if defined(_WANT_MNTOPTNAMES) || defined(_KERNEL)
329 struct mntoptnames {
330 	uint64_t o_opt;
331 	const char *o_name;
332 };
333 #define MNTOPT_NAMES							\
334 	{ MNT_ASYNC,		"asynchronous" },			\
335 	{ MNT_EXPORTED,		"NFS exported" },			\
336 	{ MNT_LOCAL,		"local" },				\
337 	{ MNT_NOATIME,		"noatime" },				\
338 	{ MNT_NOEXEC,		"noexec" },				\
339 	{ MNT_NOSUID,		"nosuid" },				\
340 	{ MNT_NOSYMFOLLOW,	"nosymfollow" },			\
341 	{ MNT_QUOTA,		"with quotas" },			\
342 	{ MNT_RDONLY,		"read-only" },				\
343 	{ MNT_SYNCHRONOUS,	"synchronous" },			\
344 	{ MNT_UNION,		"union" },				\
345 	{ MNT_NOCLUSTERR,	"noclusterr" },				\
346 	{ MNT_NOCLUSTERW,	"noclusterw" },				\
347 	{ MNT_SUIDDIR,		"suiddir" },				\
348 	{ MNT_SOFTDEP,		"soft-updates" },			\
349 	{ MNT_SUJ,		"journaled soft-updates" },		\
350 	{ MNT_MULTILABEL,	"multilabel" },				\
351 	{ MNT_ACLS,		"acls" },				\
352 	{ MNT_NFS4ACLS,		"nfsv4acls" },				\
353 	{ MNT_GJOURNAL,		"gjournal" },				\
354 	{ MNT_AUTOMOUNTED,	"automounted" },			\
355 	{ MNT_VERIFIED,		"verified" },				\
356 	{ MNT_UNTRUSTED,	"untrusted" },				\
357 	{ MNT_NOCOVER,		"nocover" },				\
358 	{ MNT_EMPTYDIR,		"emptydir" },				\
359 	{ MNT_UPDATE,		"update" },				\
360 	{ MNT_DELEXPORT,	"delexport" },				\
361 	{ MNT_RELOAD,		"reload" },				\
362 	{ MNT_FORCE,		"force" },				\
363 	{ MNT_SNAPSHOT,		"snapshot" },				\
364 	{ 0, NULL }
365 #endif
366 
367 /*
368  * User specifiable flags, stored in mnt_flag.
369  */
370 #define	MNT_RDONLY	0x0000000000000001ULL /* read only filesystem */
371 #define	MNT_SYNCHRONOUS	0x0000000000000002ULL /* fs written synchronously */
372 #define	MNT_NOEXEC	0x0000000000000004ULL /* can't exec from filesystem */
373 #define	MNT_NOSUID	0x0000000000000008ULL /* don't honor setuid fs bits */
374 #define	MNT_NFS4ACLS	0x0000000000000010ULL /* enable NFS version 4 ACLs */
375 #define	MNT_UNION	0x0000000000000020ULL /* union with underlying fs */
376 #define	MNT_ASYNC	0x0000000000000040ULL /* fs written asynchronously */
377 #define	MNT_SUIDDIR	0x0000000000100000ULL /* special SUID dir handling */
378 #define	MNT_SOFTDEP	0x0000000000200000ULL /* using soft updates */
379 #define	MNT_NOSYMFOLLOW	0x0000000000400000ULL /* do not follow symlinks */
380 #define	MNT_GJOURNAL	0x0000000002000000ULL /* GEOM journal support enabled */
381 #define	MNT_MULTILABEL	0x0000000004000000ULL /* MAC support for objects */
382 #define	MNT_ACLS	0x0000000008000000ULL /* ACL support enabled */
383 #define	MNT_NOATIME	0x0000000010000000ULL /* dont update file access time */
384 #define	MNT_NOCLUSTERR	0x0000000040000000ULL /* disable cluster read */
385 #define	MNT_NOCLUSTERW	0x0000000080000000ULL /* disable cluster write */
386 #define	MNT_SUJ		0x0000000100000000ULL /* using journaled soft updates */
387 #define	MNT_AUTOMOUNTED	0x0000000200000000ULL /* mounted by automountd(8) */
388 #define	MNT_UNTRUSTED	0x0000000800000000ULL /* filesys metadata untrusted */
389 
390 /*
391  * NFS export related mount flags.
392  */
393 #define	MNT_EXRDONLY	0x0000000000000080ULL	/* exported read only */
394 #define	MNT_EXPORTED	0x0000000000000100ULL	/* filesystem is exported */
395 #define	MNT_DEFEXPORTED	0x0000000000000200ULL	/* exported to the world */
396 #define	MNT_EXPORTANON	0x0000000000000400ULL	/* anon uid mapping for all */
397 #define	MNT_EXKERB	0x0000000000000800ULL	/* exported with Kerberos */
398 #define	MNT_EXPUBLIC	0x0000000020000000ULL	/* public export (WebNFS) */
399 #define	MNT_EXTLS	0x0000004000000000ULL /* require TLS */
400 #define	MNT_EXTLSCERT	0x0000008000000000ULL /* require TLS with client cert */
401 #define	MNT_EXTLSCERTUSER 0x0000010000000000ULL /* require TLS with user cert */
402 
403 /*
404  * Flags set by internal operations, but visible to the user.
405  */
406 #define	MNT_LOCAL	0x0000000000001000ULL /* filesystem is stored locally */
407 #define	MNT_QUOTA	0x0000000000002000ULL /* quotas are enabled on fs */
408 #define	MNT_ROOTFS	0x0000000000004000ULL /* identifies the root fs */
409 #define	MNT_USER	0x0000000000008000ULL /* mounted by a user */
410 #define	MNT_IGNORE	0x0000000000800000ULL /* do not show entry in df */
411 #define	MNT_VERIFIED	0x0000000400000000ULL /* filesystem is verified */
412 
413 /*
414  * Mask of flags that are visible to statfs().
415  * XXX I think that this could now become (~(MNT_CMDFLAGS))
416  * but the 'mount' program may need changing to handle this.
417  */
418 #define	MNT_VISFLAGMASK	(MNT_RDONLY	| MNT_SYNCHRONOUS | MNT_NOEXEC	| \
419 			MNT_NOSUID	| MNT_UNION	| MNT_SUJ	| \
420 			MNT_ASYNC	| MNT_EXRDONLY	| MNT_EXPORTED	| \
421 			MNT_DEFEXPORTED	| MNT_EXPORTANON| MNT_EXKERB	| \
422 			MNT_LOCAL	| MNT_USER	| MNT_QUOTA	| \
423 			MNT_ROOTFS	| MNT_NOATIME	| MNT_NOCLUSTERR| \
424 			MNT_NOCLUSTERW	| MNT_SUIDDIR	| MNT_SOFTDEP	| \
425 			MNT_IGNORE	| MNT_EXPUBLIC	| MNT_NOSYMFOLLOW | \
426 			MNT_GJOURNAL	| MNT_MULTILABEL | MNT_ACLS	| \
427 			MNT_NFS4ACLS	| MNT_AUTOMOUNTED | MNT_VERIFIED | \
428 			MNT_UNTRUSTED)
429 
430 /* Mask of flags that can be updated. */
431 #define	MNT_UPDATEMASK (MNT_NOSUID	| MNT_NOEXEC	| \
432 			MNT_SYNCHRONOUS	| MNT_UNION	| MNT_ASYNC	| \
433 			MNT_NOATIME | \
434 			MNT_NOSYMFOLLOW	| MNT_IGNORE	| \
435 			MNT_NOCLUSTERR	| MNT_NOCLUSTERW | MNT_SUIDDIR	| \
436 			MNT_ACLS	| MNT_USER	| MNT_NFS4ACLS	| \
437 			MNT_AUTOMOUNTED | MNT_UNTRUSTED)
438 
439 /*
440  * External filesystem command modifier flags.
441  * Unmount can use the MNT_FORCE flag.
442  * XXX: These are not STATES and really should be somewhere else.
443  * XXX: MNT_BYFSID and MNT_NONBUSY collide with MNT_ACLS and MNT_MULTILABEL,
444  *      but because MNT_ACLS and MNT_MULTILABEL are only used for mount(2),
445  *      and MNT_BYFSID and MNT_NONBUSY are only used for unmount(2),
446  *      it's harmless.
447  */
448 #define	MNT_UPDATE	0x0000000000010000ULL /* not real mount, just update */
449 #define	MNT_DELEXPORT	0x0000000000020000ULL /* delete export host lists */
450 #define	MNT_RELOAD	0x0000000000040000ULL /* reload filesystem data */
451 #define	MNT_FORCE	0x0000000000080000ULL /* force unmount or readonly */
452 #define	MNT_SNAPSHOT	0x0000000001000000ULL /* snapshot the filesystem */
453 #define	MNT_NONBUSY	0x0000000004000000ULL /* check vnode use counts. */
454 #define	MNT_BYFSID	0x0000000008000000ULL /* specify filesystem by ID. */
455 #define	MNT_NOCOVER	0x0000001000000000ULL /* Do not cover a mount point */
456 #define	MNT_EMPTYDIR	0x0000002000000000ULL /* Only mount on empty dir */
457 #define	MNT_RECURSE	0x0000100000000000ULL /* recursively unmount uppers */
458 #define	MNT_DEFERRED    0x0000200000000000ULL /* unmount in async context */
459 #define	MNT_CMDFLAGS   (MNT_UPDATE	| MNT_DELEXPORT	| MNT_RELOAD	| \
460 			MNT_FORCE	| MNT_SNAPSHOT	| MNT_NONBUSY	| \
461 			MNT_BYFSID	| MNT_NOCOVER	| MNT_EMPTYDIR	| \
462 			MNT_RECURSE	| MNT_DEFERRED)
463 
464 /*
465  * Internal filesystem control flags stored in mnt_kern_flag.
466  *
467  * MNTK_UNMOUNT locks the mount entry so that name lookup cannot
468  * proceed past the mount point.  This keeps the subtree stable during
469  * mounts and unmounts.  When non-forced unmount flushes all vnodes
470  * from the mp queue, the MNTK_UNMOUNT flag prevents insmntque() from
471  * queueing new vnodes.
472  *
473  * MNTK_UNMOUNTF permits filesystems to detect a forced unmount while
474  * dounmount() is still waiting to lock the mountpoint. This allows
475  * the filesystem to cancel operations that might otherwise deadlock
476  * with the unmount attempt (used by NFS).
477  */
478 #define MNTK_UNMOUNTF	0x00000001	/* forced unmount in progress */
479 #define MNTK_ASYNC	0x00000002	/* filtered async flag */
480 #define MNTK_SOFTDEP	0x00000004	/* async disabled by softdep */
481 #define MNTK_NOMSYNC	0x00000008	/* don't do msync */
482 #define	MNTK_DRAINING	0x00000010	/* lock draining is happening */
483 #define	MNTK_REFEXPIRE	0x00000020	/* refcount expiring is happening */
484 #define MNTK_EXTENDED_SHARED	0x00000040 /* Allow shared locking for more ops */
485 #define	MNTK_SHARED_WRITES	0x00000080 /* Allow shared locking for writes */
486 #define	MNTK_NO_IOPF	0x00000100	/* Disallow page faults during reads
487 					   and writes. Filesystem shall properly
488 					   handle i/o state on EFAULT. */
489 #define	MNTK_RECURSE		0x00000200 /* pending recursive unmount */
490 #define	MNTK_UPPER_WAITER	0x00000400 /* waiting to drain MNTK_UPPER_PENDING */
491 /* UNUSED 			0x00000800 */
492 #define	MNTK_UNLOCKED_INSMNTQUE	0x00001000 /* fs does not lock the vnode for insmntque */
493 #define	MNTK_UNMAPPED_BUFS	0x00002000
494 #define	MNTK_USES_BCACHE	0x00004000 /* FS uses the buffer cache. */
495 /* UNUSED			0x00008000 */
496 #define	MNTK_VMSETSIZE_BUG	0x00010000
497 #define	MNTK_UNIONFS	0x00020000	/* A hack for F_ISUNIONSTACK */
498 #define	MNTK_FPLOOKUP	0x00040000	/* fast path lookup is supported */
499 #define	MNTK_SUSPEND_ALL	0x00080000 /* Suspended by all-fs suspension */
500 #define	MNTK_TASKQUEUE_WAITER	0x00100000 /* Waiting on unmount taskqueue */
501 /* UNUSED			0x00200000 */
502 /* UNUSED			0x00400000 */
503 #define	MNTK_NOASYNC	0x00800000	/* disable async */
504 #define	MNTK_UNMOUNT	0x01000000	/* unmount in progress */
505 #define	MNTK_MWAIT	0x02000000	/* waiting for unmount to finish */
506 #define	MNTK_SUSPEND	0x08000000	/* request write suspension */
507 #define	MNTK_SUSPEND2	0x04000000	/* block secondary writes */
508 #define	MNTK_SUSPENDED	0x10000000	/* write operations are suspended */
509 #define	MNTK_NULL_NOCACHE	0x20000000 /* auto disable cache for nullfs
510 					      mounts over this fs */
511 #define MNTK_LOOKUP_SHARED	0x40000000 /* FS supports shared lock lookups */
512 /* UNUSED			0x80000000 */
513 
514 #ifdef _KERNEL
515 static inline int
516 MNT_SHARED_WRITES(struct mount *mp)
517 {
518 
519 	return (mp != NULL && (mp->mnt_kern_flag & MNTK_SHARED_WRITES) != 0);
520 }
521 
522 static inline int
523 MNT_EXTENDED_SHARED(struct mount *mp)
524 {
525 
526 	return (mp != NULL && (mp->mnt_kern_flag & MNTK_EXTENDED_SHARED) != 0);
527 }
528 #endif
529 
530 /*
531  * Sysctl CTL_VFS definitions.
532  *
533  * Second level identifier specifies which filesystem. Second level
534  * identifier VFS_VFSCONF returns information about all filesystems.
535  * Second level identifier VFS_GENERIC is non-terminal.
536  */
537 #define	VFS_VFSCONF		0	/* get configured filesystems */
538 #define	VFS_GENERIC		0	/* generic filesystem information */
539 /*
540  * Third level identifiers for VFS_GENERIC are given below; third
541  * level identifiers for specific filesystems are given in their
542  * mount specific header files.
543  */
544 #define VFS_MAXTYPENUM	1	/* int: highest defined filesystem type */
545 #define VFS_CONF	2	/* struct: vfsconf for filesystem given
546 				   as next argument */
547 
548 /*
549  * Flags for various system call interfaces.
550  *
551  * waitfor flags to vfs_sync() and getfsstat()
552  */
553 #define MNT_WAIT	1	/* synchronously wait for I/O to complete */
554 #define MNT_NOWAIT	2	/* start all I/O, but do not wait for it */
555 #define MNT_LAZY	3	/* push data not written by filesystem syncer */
556 #define MNT_SUSPEND	4	/* Suspend file system after sync */
557 
558 /*
559  * Generic file handle
560  */
561 struct fhandle {
562 	fsid_t	fh_fsid;	/* Filesystem id of mount point */
563 	struct	fid fh_fid;	/* Filesys specific id */
564 };
565 typedef struct fhandle	fhandle_t;
566 
567 /*
568  * Old export arguments without security flavor list
569  */
570 struct oexport_args {
571 	int	ex_flags;		/* export related flags */
572 	uid_t	ex_root;		/* mapping for root uid */
573 	struct	xucred ex_anon;		/* mapping for anonymous user */
574 	struct	sockaddr *ex_addr;	/* net address to which exported */
575 	u_char	ex_addrlen;		/* and the net address length */
576 	struct	sockaddr *ex_mask;	/* mask of valid bits in saddr */
577 	u_char	ex_masklen;		/* and the smask length */
578 	char	*ex_indexfile;		/* index file for WebNFS URLs */
579 };
580 
581 /*
582  * Not quite so old export arguments with 32bit ex_flags and xucred ex_anon.
583  */
584 #define	MAXSECFLAVORS	5
585 struct o2export_args {
586 	int	ex_flags;		/* export related flags */
587 	uid_t	ex_root;		/* mapping for root uid */
588 	struct	xucred ex_anon;		/* mapping for anonymous user */
589 	struct	sockaddr *ex_addr;	/* net address to which exported */
590 	u_char	ex_addrlen;		/* and the net address length */
591 	struct	sockaddr *ex_mask;	/* mask of valid bits in saddr */
592 	u_char	ex_masklen;		/* and the smask length */
593 	char	*ex_indexfile;		/* index file for WebNFS URLs */
594 	int	ex_numsecflavors;	/* security flavor count */
595 	int	ex_secflavors[MAXSECFLAVORS]; /* list of security flavors */
596 };
597 
598 /*
599  * Export arguments for local filesystem mount calls.
600  */
601 struct export_args {
602 	uint64_t ex_flags;		/* export related flags */
603 	uid_t	ex_root;		/* mapping for root uid */
604 	uid_t	ex_uid;			/* mapping for anonymous user */
605 	int	ex_ngroups;
606 	gid_t	*ex_groups;
607 	struct	sockaddr *ex_addr;	/* net address to which exported */
608 	u_char	ex_addrlen;		/* and the net address length */
609 	struct	sockaddr *ex_mask;	/* mask of valid bits in saddr */
610 	u_char	ex_masklen;		/* and the smask length */
611 	char	*ex_indexfile;		/* index file for WebNFS URLs */
612 	int	ex_numsecflavors;	/* security flavor count */
613 	int	ex_secflavors[MAXSECFLAVORS]; /* list of security flavors */
614 };
615 
616 /*
617  * Structure holding information for a publicly exported filesystem
618  * (WebNFS). Currently the specs allow just for one such filesystem.
619  */
620 struct nfs_public {
621 	int		np_valid;	/* Do we hold valid information */
622 	fhandle_t	np_handle;	/* Filehandle for pub fs (internal) */
623 	struct mount	*np_mount;	/* Mountpoint of exported fs */
624 	char		*np_index;	/* Index file */
625 };
626 
627 /*
628  * Filesystem configuration information. One of these exists for each
629  * type of filesystem supported by the kernel. These are searched at
630  * mount time to identify the requested filesystem.
631  *
632  * XXX: Never change the first two arguments!
633  */
634 struct vfsconf {
635 	u_int	vfc_version;		/* ABI version number */
636 	char	vfc_name[MFSNAMELEN];	/* filesystem type name */
637 	struct	vfsops *vfc_vfsops;	/* filesystem operations vector */
638 	struct	vfsops *vfc_vfsops_sd;	/* ... signal-deferred */
639 	int	vfc_typenum;		/* historic filesystem type number */
640 	int	vfc_refcount;		/* number mounted of this type */
641 	int	vfc_flags;		/* permanent flags */
642 	int	vfc_prison_flag;	/* prison allow.mount.* flag */
643 	struct	vfsoptdecl *vfc_opts;	/* mount options */
644 	TAILQ_ENTRY(vfsconf) vfc_list;	/* list of vfscons */
645 };
646 
647 /* Userland version of the struct vfsconf. */
648 struct xvfsconf {
649 	struct	vfsops *vfc_vfsops;	/* filesystem operations vector */
650 	char	vfc_name[MFSNAMELEN];	/* filesystem type name */
651 	int	vfc_typenum;		/* historic filesystem type number */
652 	int	vfc_refcount;		/* number mounted of this type */
653 	int	vfc_flags;		/* permanent flags */
654 	struct	vfsconf *vfc_next;	/* next in list */
655 };
656 
657 #ifndef BURN_BRIDGES
658 struct ovfsconf {
659 	void	*vfc_vfsops;
660 	char	vfc_name[32];
661 	int	vfc_index;
662 	int	vfc_refcount;
663 	int	vfc_flags;
664 };
665 #endif
666 
667 /*
668  * NB: these flags refer to IMPLEMENTATION properties, not properties of
669  * any actual mounts; i.e., it does not make sense to change the flags.
670  */
671 #define	VFCF_STATIC	0x00010000	/* statically compiled into kernel */
672 #define	VFCF_NETWORK	0x00020000	/* may get data over the network */
673 #define	VFCF_READONLY	0x00040000	/* writes are not implemented */
674 #define	VFCF_SYNTHETIC	0x00080000	/* data does not represent real files */
675 #define	VFCF_LOOPBACK	0x00100000	/* aliases some other mounted FS */
676 #define	VFCF_UNICODE	0x00200000	/* stores file names as Unicode */
677 #define	VFCF_JAIL	0x00400000	/* can be mounted from within a jail */
678 #define	VFCF_DELEGADMIN	0x00800000	/* supports delegated administration */
679 #define	VFCF_SBDRY	0x01000000	/* Stop at Boundary: defer stop requests
680 					   to kernel->user (AST) transition */
681 
682 typedef uint32_t fsctlop_t;
683 
684 struct vfsidctl {
685 	int		vc_vers;	/* should be VFSIDCTL_VERS1 (below) */
686 	fsid_t		vc_fsid;	/* fsid to operate on */
687 	char		vc_fstypename[MFSNAMELEN];
688 					/* type of fs 'nfs' or '*' */
689 	fsctlop_t	vc_op;		/* operation VFS_CTL_* (below) */
690 	void		*vc_ptr;	/* pointer to data structure */
691 	size_t		vc_len;		/* sizeof said structure */
692 	u_int32_t	vc_spare[12];	/* spare (must be zero) */
693 };
694 
695 /* vfsidctl API version. */
696 #define VFS_CTL_VERS1	0x01
697 
698 /*
699  * New style VFS sysctls, do not reuse/conflict with the namespace for
700  * private sysctls.
701  * All "global" sysctl ops have the 33rd bit set:
702  * 0x...1....
703  * Private sysctl ops should have the 33rd bit unset.
704  */
705 #define VFS_CTL_QUERY	0x00010001	/* anything wrong? (vfsquery) */
706 #define VFS_CTL_TIMEO	0x00010002	/* set timeout for vfs notification */
707 #define VFS_CTL_NOLOCKS	0x00010003	/* disable file locking */
708 
709 struct vfsquery {
710 	u_int32_t	vq_flags;
711 	u_int32_t	vq_spare[31];
712 };
713 
714 /* vfsquery flags */
715 #define VQ_NOTRESP	0x0001	/* server down */
716 #define VQ_NEEDAUTH	0x0002	/* server bad auth */
717 #define VQ_LOWDISK	0x0004	/* we're low on space */
718 #define VQ_MOUNT	0x0008	/* new filesystem arrived */
719 #define VQ_UNMOUNT	0x0010	/* filesystem has left */
720 #define VQ_DEAD		0x0020	/* filesystem is dead, needs force unmount */
721 #define VQ_ASSIST	0x0040	/* filesystem needs assistance from external
722 				   program */
723 #define VQ_NOTRESPLOCK	0x0080	/* server lockd down */
724 #define VQ_FLAG0100	0x0100	/* placeholder */
725 #define VQ_FLAG0200	0x0200	/* placeholder */
726 #define VQ_FLAG0400	0x0400	/* placeholder */
727 #define VQ_FLAG0800	0x0800	/* placeholder */
728 #define VQ_FLAG1000	0x1000	/* placeholder */
729 #define VQ_FLAG2000	0x2000	/* placeholder */
730 #define VQ_FLAG4000	0x4000	/* placeholder */
731 #define VQ_FLAG8000	0x8000	/* placeholder */
732 
733 #ifdef _KERNEL
734 /* Point a sysctl request at a vfsidctl's data. */
735 #define VCTLTOREQ(vc, req)						\
736 	do {								\
737 		(req)->newptr = (vc)->vc_ptr;				\
738 		(req)->newlen = (vc)->vc_len;				\
739 		(req)->newidx = 0;					\
740 	} while (0)
741 #endif
742 
743 struct iovec;
744 struct uio;
745 
746 #ifdef _KERNEL
747 
748 /*
749  * vfs_busy specific flags and mask.
750  */
751 #define	MBF_NOWAIT	0x01
752 #define	MBF_MNTLSTLOCK	0x02
753 #define	MBF_MASK	(MBF_NOWAIT | MBF_MNTLSTLOCK)
754 
755 #ifdef MALLOC_DECLARE
756 MALLOC_DECLARE(M_MOUNT);
757 MALLOC_DECLARE(M_STATFS);
758 #endif
759 extern int maxvfsconf;		/* highest defined filesystem type */
760 
761 TAILQ_HEAD(vfsconfhead, vfsconf);
762 extern struct vfsconfhead vfsconf;
763 
764 /*
765  * Operations supported on mounted filesystem.
766  */
767 struct mount_args;
768 struct nameidata;
769 struct sysctl_req;
770 struct mntarg;
771 
772 /*
773  * N.B., vfs_cmount is the ancient vfsop invoked by the old mount(2) syscall.
774  * The new way is vfs_mount.
775  *
776  * vfs_cmount implementations typically translate arguments from their
777  * respective old per-FS structures into the key-value list supported by
778  * nmount(2), then use kernel_mount(9) to mimic nmount(2) from kernelspace.
779  *
780  * Filesystems with mounters that use nmount(2) do not need to and should not
781  * implement vfs_cmount.  Hopefully a future cleanup can remove vfs_cmount and
782  * mount(2) entirely.
783  */
784 typedef int vfs_cmount_t(struct mntarg *ma, void *data, uint64_t flags);
785 typedef int vfs_unmount_t(struct mount *mp, int mntflags);
786 typedef int vfs_root_t(struct mount *mp, int flags, struct vnode **vpp);
787 typedef	int vfs_quotactl_t(struct mount *mp, int cmds, uid_t uid, void *arg,
788 		    bool *mp_busy);
789 typedef	int vfs_statfs_t(struct mount *mp, struct statfs *sbp);
790 typedef	int vfs_sync_t(struct mount *mp, int waitfor);
791 typedef	int vfs_vget_t(struct mount *mp, ino_t ino, int flags,
792 		    struct vnode **vpp);
793 typedef	int vfs_fhtovp_t(struct mount *mp, struct fid *fhp,
794 		    int flags, struct vnode **vpp);
795 typedef	int vfs_checkexp_t(struct mount *mp, struct sockaddr *nam,
796 		    uint64_t *extflagsp, struct ucred **credanonp,
797 		    int *numsecflavors, int *secflavors);
798 typedef	int vfs_init_t(struct vfsconf *);
799 typedef	int vfs_uninit_t(struct vfsconf *);
800 typedef	int vfs_extattrctl_t(struct mount *mp, int cmd,
801 		    struct vnode *filename_vp, int attrnamespace,
802 		    const char *attrname);
803 typedef	int vfs_mount_t(struct mount *mp);
804 typedef int vfs_sysctl_t(struct mount *mp, fsctlop_t op,
805 		    struct sysctl_req *req);
806 typedef void vfs_susp_clean_t(struct mount *mp);
807 typedef void vfs_notify_lowervp_t(struct mount *mp, struct vnode *lowervp);
808 typedef void vfs_purge_t(struct mount *mp);
809 struct sbuf;
810 typedef int vfs_report_lockf_t(struct mount *mp, struct sbuf *sb);
811 
812 struct vfsops {
813 	vfs_mount_t		*vfs_mount;
814 	vfs_cmount_t		*vfs_cmount;
815 	vfs_unmount_t		*vfs_unmount;
816 	vfs_root_t		*vfs_root;
817 	vfs_root_t		*vfs_cachedroot;
818 	vfs_quotactl_t		*vfs_quotactl;
819 	vfs_statfs_t		*vfs_statfs;
820 	vfs_sync_t		*vfs_sync;
821 	vfs_vget_t		*vfs_vget;
822 	vfs_fhtovp_t		*vfs_fhtovp;
823 	vfs_checkexp_t		*vfs_checkexp;
824 	vfs_init_t		*vfs_init;
825 	vfs_uninit_t		*vfs_uninit;
826 	vfs_extattrctl_t	*vfs_extattrctl;
827 	vfs_sysctl_t		*vfs_sysctl;
828 	vfs_susp_clean_t	*vfs_susp_clean;
829 	vfs_notify_lowervp_t	*vfs_reclaim_lowervp;
830 	vfs_notify_lowervp_t	*vfs_unlink_lowervp;
831 	vfs_purge_t		*vfs_purge;
832 	vfs_report_lockf_t	*vfs_report_lockf;
833 	vfs_mount_t		*vfs_spare[6];	/* spares for ABI compat */
834 };
835 
836 vfs_statfs_t	__vfs_statfs;
837 
838 #define	VFS_MOUNT(MP) ({						\
839 	int _rc;							\
840 									\
841 	TSRAW(curthread, TS_ENTER, "VFS_MOUNT", (MP)->mnt_vfc->vfc_name);\
842 	_rc = (*(MP)->mnt_op->vfs_mount)(MP);				\
843 	TSRAW(curthread, TS_EXIT, "VFS_MOUNT", (MP)->mnt_vfc->vfc_name);\
844 	_rc; })
845 
846 #define	VFS_UNMOUNT(MP, FORCE) ({					\
847 	int _rc;							\
848 									\
849 	_rc = (*(MP)->mnt_op->vfs_unmount)(MP, FORCE);			\
850 	_rc; })
851 
852 #define	VFS_ROOT(MP, FLAGS, VPP) ({					\
853 	int _rc;							\
854 									\
855 	_rc = (*(MP)->mnt_op->vfs_root)(MP, FLAGS, VPP);		\
856 	_rc; })
857 
858 #define	VFS_CACHEDROOT(MP, FLAGS, VPP) ({				\
859 	int _rc;							\
860 									\
861 	_rc = (*(MP)->mnt_op->vfs_cachedroot)(MP, FLAGS, VPP);		\
862 	_rc; })
863 
864 #define	VFS_QUOTACTL(MP, C, U, A, MP_BUSY) ({				\
865 	int _rc;							\
866 									\
867 	_rc = (*(MP)->mnt_op->vfs_quotactl)(MP, C, U, A, MP_BUSY);	\
868 	_rc; })
869 
870 #define	VFS_STATFS(MP, SBP) ({						\
871 	int _rc;							\
872 									\
873 	_rc = __vfs_statfs((MP), (SBP));				\
874 	_rc; })
875 
876 #define	VFS_SYNC(MP, WAIT) ({						\
877 	int _rc;							\
878 									\
879 	_rc = (*(MP)->mnt_op->vfs_sync)(MP, WAIT);			\
880 	_rc; })
881 
882 #define	VFS_VGET(MP, INO, FLAGS, VPP) ({				\
883 	int _rc;							\
884 									\
885 	_rc = (*(MP)->mnt_op->vfs_vget)(MP, INO, FLAGS, VPP);		\
886 	_rc; })
887 
888 #define	VFS_FHTOVP(MP, FIDP, FLAGS, VPP) ({				\
889 	int _rc;							\
890 									\
891 	_rc = (*(MP)->mnt_op->vfs_fhtovp)(MP, FIDP, FLAGS, VPP);	\
892 	_rc; })
893 
894 #define	VFS_CHECKEXP(MP, NAM, EXFLG, CRED, NUMSEC, SEC) ({		\
895 	int _rc;							\
896 									\
897 	_rc = (*(MP)->mnt_op->vfs_checkexp)(MP, NAM, EXFLG, CRED, NUMSEC,\
898 	    SEC);							\
899 	_rc; })
900 
901 #define	VFS_EXTATTRCTL(MP, C, FN, NS, N) ({				\
902 	int _rc;							\
903 									\
904 	_rc = (*(MP)->mnt_op->vfs_extattrctl)(MP, C, FN, NS, N);	\
905 	_rc; })
906 
907 #define	VFS_SYSCTL(MP, OP, REQ) ({					\
908 	int _rc;							\
909 									\
910 	_rc = (*(MP)->mnt_op->vfs_sysctl)(MP, OP, REQ);			\
911 	_rc; })
912 
913 #define	VFS_SUSP_CLEAN(MP) do {						\
914 	if (*(MP)->mnt_op->vfs_susp_clean != NULL) {			\
915 		(*(MP)->mnt_op->vfs_susp_clean)(MP);			\
916 	}								\
917 } while (0)
918 
919 #define	VFS_RECLAIM_LOWERVP(MP, VP) do {				\
920 	if (*(MP)->mnt_op->vfs_reclaim_lowervp != NULL) {		\
921 		(*(MP)->mnt_op->vfs_reclaim_lowervp)((MP), (VP));	\
922 	}								\
923 } while (0)
924 
925 #define	VFS_UNLINK_LOWERVP(MP, VP) do {					\
926 	if (*(MP)->mnt_op->vfs_unlink_lowervp != NULL) {		\
927 		(*(MP)->mnt_op->vfs_unlink_lowervp)((MP), (VP));	\
928 	}								\
929 } while (0)
930 
931 #define	VFS_PURGE(MP) do {						\
932 	if (*(MP)->mnt_op->vfs_purge != NULL) {				\
933 		(*(MP)->mnt_op->vfs_purge)(MP);				\
934 	}								\
935 } while (0)
936 
937 #define VFS_KNOTE_LOCKED(vp, hint) do					\
938 {									\
939 	VN_KNOTE((vp), (hint), KNF_LISTLOCKED);				\
940 } while (0)
941 
942 #define VFS_KNOTE_UNLOCKED(vp, hint) do					\
943 {									\
944 	VN_KNOTE((vp), (hint), 0);					\
945 } while (0)
946 
947 #include <sys/module.h>
948 
949 /*
950  * Version numbers.
951  */
952 #define VFS_VERSION_00	0x19660120
953 #define VFS_VERSION_01	0x20121030
954 #define VFS_VERSION_02	0x20180504
955 #define VFS_VERSION	VFS_VERSION_02
956 
957 #define VFS_SET(vfsops, fsname, flags) \
958 	static struct vfsconf fsname ## _vfsconf = {		\
959 		.vfc_version = VFS_VERSION,			\
960 		.vfc_name = #fsname,				\
961 		.vfc_vfsops = &vfsops,				\
962 		.vfc_typenum = -1,				\
963 		.vfc_flags = flags,				\
964 	};							\
965 	static moduledata_t fsname ## _mod = {			\
966 		#fsname,					\
967 		vfs_modevent,					\
968 		& fsname ## _vfsconf				\
969 	};							\
970 	DECLARE_MODULE(fsname, fsname ## _mod, SI_SUB_VFS, SI_ORDER_MIDDLE)
971 
972 enum vfs_notify_upper_type {
973 	VFS_NOTIFY_UPPER_RECLAIM,
974 	VFS_NOTIFY_UPPER_UNLINK,
975 };
976 
977 /*
978  * exported vnode operations
979  */
980 
981 int	dounmount(struct mount *, uint64_t, struct thread *);
982 
983 int	kernel_mount(struct mntarg *ma, uint64_t flags);
984 struct mntarg *mount_arg(struct mntarg *ma, const char *name, const void *val, int len);
985 struct mntarg *mount_argb(struct mntarg *ma, int flag, const char *name);
986 struct mntarg *mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...);
987 struct mntarg *mount_argsu(struct mntarg *ma, const char *name, const void *val, int len);
988 void	statfs_scale_blocks(struct statfs *sf, long max_size);
989 struct vfsconf *vfs_byname(const char *);
990 struct vfsconf *vfs_byname_kld(const char *, struct thread *td, int *);
991 void	vfs_mount_destroy(struct mount *);
992 void	vfs_event_signal(fsid_t *, u_int32_t, intptr_t);
993 void	vfs_freeopts(struct vfsoptlist *opts);
994 void	vfs_deleteopt(struct vfsoptlist *opts, const char *name);
995 int	vfs_buildopts(struct uio *auio, struct vfsoptlist **options);
996 int	vfs_flagopt(struct vfsoptlist *opts, const char *name, uint64_t *w,
997 	    uint64_t val);
998 int	vfs_getopt(struct vfsoptlist *, const char *, void **, int *);
999 int	vfs_getopt_pos(struct vfsoptlist *opts, const char *name);
1000 int	vfs_getopt_size(struct vfsoptlist *opts, const char *name,
1001 	    off_t *value);
1002 char	*vfs_getopts(struct vfsoptlist *, const char *, int *error);
1003 int	vfs_copyopt(struct vfsoptlist *, const char *, void *, int);
1004 int	vfs_filteropt(struct vfsoptlist *, const char **legal);
1005 void	vfs_opterror(struct vfsoptlist *opts, const char *fmt, ...);
1006 int	vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...);
1007 int	vfs_setopt(struct vfsoptlist *opts, const char *name, void *value,
1008 	    int len);
1009 int	vfs_setopt_part(struct vfsoptlist *opts, const char *name, void *value,
1010 	    int len);
1011 int	vfs_setopts(struct vfsoptlist *opts, const char *name,
1012 	    const char *value);
1013 int	vfs_setpublicfs			    /* set publicly exported fs */
1014 	    (struct mount *, struct netexport *, struct export_args *);
1015 void	vfs_periodic(struct mount *, int);
1016 int	vfs_busy(struct mount *, int);
1017 int	vfs_export			 /* process mount export info */
1018 	    (struct mount *, struct export_args *);
1019 void	vfs_allocate_syncvnode(struct mount *);
1020 void	vfs_deallocate_syncvnode(struct mount *);
1021 int	vfs_donmount(struct thread *td, uint64_t fsflags,
1022 	    struct uio *fsoptions);
1023 void	vfs_getnewfsid(struct mount *);
1024 struct	mount *vfs_getvfs(fsid_t *);      /* return vfs given fsid */
1025 struct	mount *vfs_busyfs(fsid_t *);
1026 int	vfs_modevent(module_t, int, void *);
1027 void	vfs_mount_error(struct mount *, const char *, ...);
1028 void	vfs_mountroot(void);			/* mount our root filesystem */
1029 void	vfs_mountedfrom(struct mount *, const char *from);
1030 void	vfs_notify_upper(struct vnode *, enum vfs_notify_upper_type);
1031 struct mount *vfs_ref_from_vp(struct vnode *);
1032 void	vfs_ref(struct mount *);
1033 void	vfs_rel(struct mount *);
1034 struct mount *vfs_mount_alloc(struct vnode *, struct vfsconf *, const char *,
1035 	    struct ucred *);
1036 int	vfs_suser(struct mount *, struct thread *);
1037 void	vfs_unbusy(struct mount *);
1038 void	vfs_unmountall(void);
1039 struct mount *vfs_register_upper_from_vp(struct vnode *,
1040 	    struct mount *ump, struct mount_upper_node *);
1041 void	vfs_register_for_notification(struct mount *, struct mount *,
1042 	    struct mount_upper_node *);
1043 void	vfs_unregister_for_notification(struct mount *,
1044 	    struct mount_upper_node *);
1045 void	vfs_unregister_upper(struct mount *, struct mount_upper_node *);
1046 int	vfs_remount_ro(struct mount *mp);
1047 int	vfs_report_lockf(struct mount *mp, struct sbuf *sb);
1048 
1049 extern	TAILQ_HEAD(mntlist, mount) mountlist;	/* mounted filesystem list */
1050 extern	struct mtx_padalign mountlist_mtx;
1051 extern	struct nfs_public nfs_pub;
1052 extern	struct sx vfsconf_sx;
1053 #define	vfsconf_lock()		sx_xlock(&vfsconf_sx)
1054 #define	vfsconf_unlock()	sx_xunlock(&vfsconf_sx)
1055 #define	vfsconf_slock()		sx_slock(&vfsconf_sx)
1056 #define	vfsconf_sunlock()	sx_sunlock(&vfsconf_sx)
1057 struct vnode *mntfs_allocvp(struct mount *, struct vnode *);
1058 void   mntfs_freevp(struct vnode *);
1059 
1060 /*
1061  * Declarations for these vfs default operations are located in
1062  * kern/vfs_default.c.  They will be automatically used to replace
1063  * null entries in VFS ops tables when registering a new filesystem
1064  * type in the global table.
1065  */
1066 vfs_root_t		vfs_stdroot;
1067 vfs_quotactl_t		vfs_stdquotactl;
1068 vfs_statfs_t		vfs_stdstatfs;
1069 vfs_sync_t		vfs_stdsync;
1070 vfs_sync_t		vfs_stdnosync;
1071 vfs_vget_t		vfs_stdvget;
1072 vfs_fhtovp_t		vfs_stdfhtovp;
1073 vfs_checkexp_t		vfs_stdcheckexp;
1074 vfs_init_t		vfs_stdinit;
1075 vfs_uninit_t		vfs_stduninit;
1076 vfs_extattrctl_t	vfs_stdextattrctl;
1077 vfs_sysctl_t		vfs_stdsysctl;
1078 
1079 void	syncer_suspend(void);
1080 void	syncer_resume(void);
1081 
1082 struct vnode *vfs_cache_root_clear(struct mount *);
1083 void	vfs_cache_root_set(struct mount *, struct vnode *);
1084 
1085 void	vfs_op_barrier_wait(struct mount *);
1086 void	vfs_op_enter(struct mount *);
1087 void	vfs_op_exit_locked(struct mount *);
1088 void	vfs_op_exit(struct mount *);
1089 
1090 #ifdef DIAGNOSTIC
1091 void	vfs_assert_mount_counters(struct mount *);
1092 void	vfs_dump_mount_counters(struct mount *);
1093 #else
1094 #define vfs_assert_mount_counters(mp) do { } while (0)
1095 #define vfs_dump_mount_counters(mp) do { } while (0)
1096 #endif
1097 
1098 enum mount_counter { MNT_COUNT_REF, MNT_COUNT_LOCKREF, MNT_COUNT_WRITEOPCOUNT };
1099 int	vfs_mount_fetch_counter(struct mount *, enum mount_counter);
1100 
1101 void suspend_all_fs(void);
1102 void resume_all_fs(void);
1103 
1104 /*
1105  * Code transitioning mnt_vfs_ops to > 0 issues IPIs until it observes
1106  * all CPUs not executing code enclosed by thread_in_ops_pcpu variable.
1107  *
1108  * This provides an invariant that by the time the last CPU is observed not
1109  * executing, everyone else entering will see the counter > 0 and exit.
1110  *
1111  * Note there is no barrier between vfs_ops and the rest of the code in the
1112  * section. It is not necessary as the writer has to wait for everyone to drain
1113  * before making any changes or only make changes safe while the section is
1114  * executed.
1115  */
1116 #define	vfs_mount_pcpu(mp)		zpcpu_get(mp->mnt_pcpu)
1117 #define	vfs_mount_pcpu_remote(mp, cpu)	zpcpu_get_cpu(mp->mnt_pcpu, cpu)
1118 
1119 #define vfs_op_thread_entered(mp) ({				\
1120 	MPASS(curthread->td_critnest > 0);			\
1121 	struct mount_pcpu *_mpcpu = vfs_mount_pcpu(mp);		\
1122 	_mpcpu->mntp_thread_in_ops == 1;			\
1123 })
1124 
1125 #define vfs_op_thread_enter_crit(mp, _mpcpu) ({			\
1126 	bool _retval_crit = true;				\
1127 	MPASS(curthread->td_critnest > 0);			\
1128 	_mpcpu = vfs_mount_pcpu(mp);				\
1129 	MPASS(mpcpu->mntp_thread_in_ops == 0);			\
1130 	_mpcpu->mntp_thread_in_ops = 1;				\
1131 	atomic_interrupt_fence();					\
1132 	if (__predict_false(mp->mnt_vfs_ops > 0)) {		\
1133 		vfs_op_thread_exit_crit(mp, _mpcpu);		\
1134 		_retval_crit = false;				\
1135 	}							\
1136 	_retval_crit;						\
1137 })
1138 
1139 #define vfs_op_thread_enter(mp, _mpcpu) ({			\
1140 	bool _retval;						\
1141 	critical_enter();					\
1142 	_retval = vfs_op_thread_enter_crit(mp, _mpcpu);		\
1143 	if (__predict_false(!_retval))				\
1144 		critical_exit();				\
1145 	_retval;						\
1146 })
1147 
1148 #define vfs_op_thread_exit_crit(mp, _mpcpu) do {		\
1149 	MPASS(_mpcpu == vfs_mount_pcpu(mp));			\
1150 	MPASS(_mpcpu->mntp_thread_in_ops == 1);			\
1151 	atomic_interrupt_fence();					\
1152 	_mpcpu->mntp_thread_in_ops = 0;				\
1153 } while (0)
1154 
1155 #define vfs_op_thread_exit(mp, _mpcpu) do {			\
1156 	vfs_op_thread_exit_crit(mp, _mpcpu);			\
1157 	critical_exit();					\
1158 } while (0)
1159 
1160 #define vfs_mp_count_add_pcpu(_mpcpu, count, val) do {		\
1161 	MPASS(_mpcpu->mntp_thread_in_ops == 1);			\
1162 	_mpcpu->mntp_##count += val;				\
1163 } while (0)
1164 
1165 #define vfs_mp_count_sub_pcpu(_mpcpu, count, val) do {		\
1166 	MPASS(_mpcpu->mntp_thread_in_ops == 1);			\
1167 	_mpcpu->mntp_##count -= val;				\
1168 } while (0)
1169 
1170 #else /* !_KERNEL */
1171 
1172 #include <sys/cdefs.h>
1173 
1174 struct stat;
1175 
1176 __BEGIN_DECLS
1177 int	fhlink(struct fhandle *, const char *);
1178 int	fhlinkat(struct fhandle *, int, const char *);
1179 int	fhopen(const struct fhandle *, int);
1180 int	fhreadlink(struct fhandle *, char *, size_t);
1181 int	fhstat(const struct fhandle *, struct stat *);
1182 int	fhstatfs(const struct fhandle *, struct statfs *);
1183 int	fstatfs(int, struct statfs *);
1184 int	getfh(const char *, fhandle_t *);
1185 int	getfhat(int, char *, struct fhandle *, int);
1186 int	getfsstat(struct statfs *, long, int);
1187 int	getmntinfo(struct statfs **, int);
1188 int	lgetfh(const char *, fhandle_t *);
1189 int	mount(const char *, const char *, int, void *);
1190 int	nmount(struct iovec *, unsigned int, int);
1191 int	statfs(const char *, struct statfs *);
1192 int	unmount(const char *, int);
1193 
1194 /* C library stuff */
1195 int	getvfsbyname(const char *, struct xvfsconf *);
1196 __END_DECLS
1197 
1198 #endif /* _KERNEL */
1199 
1200 #endif /* !_SYS_MOUNT_H_ */
1201