usr/src/boot/sys/sys/mount.h

/*-
 * Copyright (c) 1989, 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)mount.h	8.21 (Berkeley) 5/20/95
 * $FreeBSD$
 */

#ifndef _SYS_MOUNT_H_
#define _SYS_MOUNT_H_

#include <sys/ucred.h>
#include <sys/queue.h>
#ifdef _KERNEL
#include <sys/lock.h>
#include <sys/lockmgr.h>
#include <sys/_mutex.h>
#include <sys/_sx.h>
#endif

/*
 * NOTE: When changing statfs structure, mount structure, MNT_* flags or
 * MNTK_* flags also update DDB show mount command in vfs_subr.c.
 */

typedef struct fsid { int32_t val[2]; } fsid_t;	/* filesystem id type */

/*
 * File identifier.
 * These are unique per filesystem on a single machine.
 */
#define	MAXFIDSZ	16

struct fid {
	u_short		fid_len;		/* length of data in bytes */
	u_short		fid_data0;		/* force longword alignment */
	char		fid_data[MAXFIDSZ];	/* data (variable length) */
};

/*
 * filesystem statistics
 */
#define	MFSNAMELEN	16		/* length of type name including null */
#define	MNAMELEN	88		/* size of on/from name bufs */
#define	STATFS_VERSION	0x20030518	/* current version number */
struct statfs {
	uint32_t f_version;		/* structure version number */
	uint32_t f_type;		/* type of filesystem */
	uint64_t f_flags;		/* copy of mount exported flags */
	uint64_t f_bsize;		/* filesystem fragment size */
	uint64_t f_iosize;		/* optimal transfer block size */
	uint64_t f_blocks;		/* total data blocks in filesystem */
	uint64_t f_bfree;		/* free blocks in filesystem */
	int64_t	 f_bavail;		/* free blocks avail to non-superuser */
	uint64_t f_files;		/* total file nodes in filesystem */
	int64_t	 f_ffree;		/* free nodes avail to non-superuser */
	uint64_t f_syncwrites;		/* count of sync writes since mount */
	uint64_t f_asyncwrites;		/* count of async writes since mount */
	uint64_t f_syncreads;		/* count of sync reads since mount */
	uint64_t f_asyncreads;		/* count of async reads since mount */
	uint64_t f_spare[10];		/* unused spare */
	uint32_t f_namemax;		/* maximum filename length */
	uid_t	  f_owner;		/* user that mounted the filesystem */
	fsid_t	  f_fsid;		/* filesystem id */
	char	  f_charspare[80];	    /* spare string space */
	char	  f_fstypename[MFSNAMELEN]; /* filesystem type name */
	char	  f_mntfromname[MNAMELEN];  /* mounted filesystem */
	char	  f_mntonname[MNAMELEN];    /* directory on which mounted */
};

#ifdef _KERNEL
#define	OMFSNAMELEN	16	/* length of fs type name, including null */
#define	OMNAMELEN	(88 - 2 * sizeof(long))	/* size of on/from name bufs */

/* XXX getfsstat.2 is out of date with write and read counter changes here. */
/* XXX statfs.2 is out of date with read counter changes here. */
struct ostatfs {
	long	f_spare2;		/* placeholder */
	long	f_bsize;		/* fundamental filesystem block size */
	long	f_iosize;		/* optimal transfer block size */
	long	f_blocks;		/* total data blocks in filesystem */
	long	f_bfree;		/* free blocks in fs */
	long	f_bavail;		/* free blocks avail to non-superuser */
	long	f_files;		/* total file nodes in filesystem */
	long	f_ffree;		/* free file nodes in fs */
	fsid_t	f_fsid;			/* filesystem id */
	uid_t	f_owner;		/* user that mounted the filesystem */
	int	f_type;			/* type of filesystem */
	int	f_flags;		/* copy of mount exported flags */
	long	f_syncwrites;		/* count of sync writes since mount */
	long	f_asyncwrites;		/* count of async writes since mount */
	char	f_fstypename[OMFSNAMELEN]; /* fs type name */
	char	f_mntonname[OMNAMELEN];	/* directory on which mounted */
	long	f_syncreads;		/* count of sync reads since mount */
	long	f_asyncreads;		/* count of async reads since mount */
	short	f_spares1;		/* unused spare */
	char	f_mntfromname[OMNAMELEN];/* mounted filesystem */
	short	f_spares2;		/* unused spare */
	/*
	 * XXX on machines where longs are aligned to 8-byte boundaries, there
	 * is an unnamed int32_t here.  This spare was after the apparent end
	 * of the struct until we bit off the read counters from f_mntonname.
	 */
	long	f_spare[2];		/* unused spare */
};

TAILQ_HEAD(vnodelst, vnode);

/* Mount options list */
TAILQ_HEAD(vfsoptlist, vfsopt);
struct vfsopt {
	TAILQ_ENTRY(vfsopt) link;
	char	*name;
	void	*value;
	int	len;
	int	pos;
	int	seen;
};

/*
 * Structure per mounted filesystem.  Each mounted filesystem has an
 * array of operations and an instance record.  The filesystems are
 * put on a doubly linked list.
 *
 * Lock reference:
 *	m - mountlist_mtx
 *	i - interlock
 *	v - vnode freelist mutex
 *
 * Unmarked fields are considered stable as long as a ref is held.
 *
 */
struct mount {
	struct mtx	mnt_mtx;		/* mount structure interlock */
	int		mnt_gen;		/* struct mount generation */
#define	mnt_startzero	mnt_list
	TAILQ_ENTRY(mount) mnt_list;		/* (m) mount list */
	struct vfsops	*mnt_op;		/* operations on fs */
	struct vfsconf	*mnt_vfc;		/* configuration info */
	struct vnode	*mnt_vnodecovered;	/* vnode we mounted on */
	struct vnode	*mnt_syncer;		/* syncer vnode */
	int		mnt_ref;		/* (i) Reference count */
	struct vnodelst	mnt_nvnodelist;		/* (i) list of vnodes */
	int		mnt_nvnodelistsize;	/* (i) # of vnodes */
	struct vnodelst	mnt_activevnodelist;	/* (v) list of active vnodes */
	int		mnt_activevnodelistsize;/* (v) # of active vnodes */
	int		mnt_writeopcount;	/* (i) write syscalls pending */
	int		mnt_kern_flag;		/* (i) kernel only flags */
	uint64_t	mnt_flag;		/* (i) flags shared with user */
	struct vfsoptlist *mnt_opt;		/* current mount options */
	struct vfsoptlist *mnt_optnew;		/* new options passed to fs */
	int		mnt_maxsymlinklen;	/* max size of short symlink */
	struct statfs	mnt_stat;		/* cache of filesystem stats */
	struct ucred	*mnt_cred;		/* credentials of mounter */
	void *		mnt_data;		/* private data */
	time_t		mnt_time;		/* last time written*/
	int		mnt_iosize_max;		/* max size for clusters, etc */
	struct netexport *mnt_export;		/* export list */
	struct label	*mnt_label;		/* MAC label for the fs */
	u_int		mnt_hashseed;		/* Random seed for vfs_hash */
	int		mnt_lockref;		/* (i) Lock reference count */
	int		mnt_secondary_writes;   /* (i) # of secondary writes */
	int		mnt_secondary_accwrites;/* (i) secondary wr. starts */
	struct thread	*mnt_susp_owner;	/* (i) thread owning suspension */
#define	mnt_endzero	mnt_gjprovider
	char		*mnt_gjprovider;	/* gjournal provider name */
	struct lock	mnt_explock;		/* vfs_export walkers lock */
	TAILQ_ENTRY(mount) mnt_upper_link;	/* (m) we in the all uppers */
	TAILQ_HEAD(, mount) mnt_uppers;		/* (m) upper mounts over us*/
};

/*
 * Definitions for MNT_VNODE_FOREACH_ALL.
 */
struct vnode *__mnt_vnode_next_all(struct vnode **mvp, struct mount *mp);
struct vnode *__mnt_vnode_first_all(struct vnode **mvp, struct mount *mp);
void          __mnt_vnode_markerfree_all(struct vnode **mvp, struct mount *mp);

#define MNT_VNODE_FOREACH_ALL(vp, mp, mvp)				\
	for (vp = __mnt_vnode_first_all(&(mvp), (mp));			\
		(vp) != NULL; vp = __mnt_vnode_next_all(&(mvp), (mp)))

#define MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp)				\
	do {								\
		MNT_ILOCK(mp);						\
		__mnt_vnode_markerfree_all(&(mvp), (mp));		\
		/* MNT_IUNLOCK(mp); -- done in above function */	\
		mtx_assert(MNT_MTX(mp), MA_NOTOWNED);			\
	} while (0)

/*
 * Definitions for MNT_VNODE_FOREACH_ACTIVE.
 */
struct vnode *__mnt_vnode_next_active(struct vnode **mvp, struct mount *mp);
struct vnode *__mnt_vnode_first_active(struct vnode **mvp, struct mount *mp);
void          __mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *);

#define MNT_VNODE_FOREACH_ACTIVE(vp, mp, mvp) 				\
	for (vp = __mnt_vnode_first_active(&(mvp), (mp)); 		\
		(vp) != NULL; vp = __mnt_vnode_next_active(&(mvp), (mp)))

#define MNT_VNODE_FOREACH_ACTIVE_ABORT(mp, mvp)				\
	__mnt_vnode_markerfree_active(&(mvp), (mp))

#define	MNT_ILOCK(mp)	mtx_lock(&(mp)->mnt_mtx)
#define	MNT_ITRYLOCK(mp) mtx_trylock(&(mp)->mnt_mtx)
#define	MNT_IUNLOCK(mp)	mtx_unlock(&(mp)->mnt_mtx)
#define	MNT_MTX(mp)	(&(mp)->mnt_mtx)
#define	MNT_REF(mp)	(mp)->mnt_ref++
#define	MNT_REL(mp)	do {						\
	KASSERT((mp)->mnt_ref > 0, ("negative mnt_ref"));		\
	(mp)->mnt_ref--;						\
	if ((mp)->mnt_ref == 0)						\
		wakeup((mp));						\
} while (0)

#endif /* _KERNEL */

/*
 * User specifiable flags, stored in mnt_flag.
 */
#define	MNT_RDONLY	0x0000000000000001ULL /* read only filesystem */
#define	MNT_SYNCHRONOUS	0x0000000000000002ULL /* fs written synchronously */
#define	MNT_NOEXEC	0x0000000000000004ULL /* can't exec from filesystem */
#define	MNT_NOSUID	0x0000000000000008ULL /* don't honor setuid fs bits */
#define	MNT_NFS4ACLS	0x0000000000000010ULL /* enable NFS version 4 ACLs */
#define	MNT_UNION	0x0000000000000020ULL /* union with underlying fs */
#define	MNT_ASYNC	0x0000000000000040ULL /* fs written asynchronously */
#define	MNT_SUIDDIR	0x0000000000100000ULL /* special SUID dir handling */
#define	MNT_SOFTDEP	0x0000000000200000ULL /* using soft updates */
#define	MNT_NOSYMFOLLOW	0x0000000000400000ULL /* do not follow symlinks */
#define	MNT_GJOURNAL	0x0000000002000000ULL /* GEOM journal support enabled */
#define	MNT_MULTILABEL	0x0000000004000000ULL /* MAC support for objects */
#define	MNT_ACLS	0x0000000008000000ULL /* ACL support enabled */
#define	MNT_NOATIME	0x0000000010000000ULL /* dont update file access time */
#define	MNT_NOCLUSTERR	0x0000000040000000ULL /* disable cluster read */
#define	MNT_NOCLUSTERW	0x0000000080000000ULL /* disable cluster write */
#define	MNT_SUJ		0x0000000100000000ULL /* using journaled soft updates */
#define	MNT_AUTOMOUNTED	0x0000000200000000ULL /* mounted by automountd(8) */

/*
 * NFS export related mount flags.
 */
#define	MNT_EXRDONLY	0x0000000000000080ULL	/* exported read only */
#define	MNT_EXPORTED	0x0000000000000100ULL	/* filesystem is exported */
#define	MNT_DEFEXPORTED	0x0000000000000200ULL	/* exported to the world */
#define	MNT_EXPORTANON	0x0000000000000400ULL	/* anon uid mapping for all */
#define	MNT_EXKERB	0x0000000000000800ULL	/* exported with Kerberos */
#define	MNT_EXPUBLIC	0x0000000020000000ULL	/* public export (WebNFS) */

/*
 * Flags set by internal operations,
 * but visible to the user.
 * XXX some of these are not quite right.. (I've never seen the root flag set)
 */
#define	MNT_LOCAL	0x0000000000001000ULL /* filesystem is stored locally */
#define	MNT_QUOTA	0x0000000000002000ULL /* quotas are enabled on fs */
#define	MNT_ROOTFS	0x0000000000004000ULL /* identifies the root fs */
#define	MNT_USER	0x0000000000008000ULL /* mounted by a user */
#define	MNT_IGNORE	0x0000000000800000ULL /* do not show entry in df */

/*
 * Mask of flags that are visible to statfs().
 * XXX I think that this could now become (~(MNT_CMDFLAGS))
 * but the 'mount' program may need changing to handle this.
 */
#define	MNT_VISFLAGMASK	(MNT_RDONLY	| MNT_SYNCHRONOUS | MNT_NOEXEC	| \
			MNT_NOSUID	| MNT_UNION	| MNT_SUJ	| \
			MNT_ASYNC	| MNT_EXRDONLY	| MNT_EXPORTED	| \
			MNT_DEFEXPORTED	| MNT_EXPORTANON| MNT_EXKERB	| \
			MNT_LOCAL	| MNT_USER	| MNT_QUOTA	| \
			MNT_ROOTFS	| MNT_NOATIME	| MNT_NOCLUSTERR| \
			MNT_NOCLUSTERW	| MNT_SUIDDIR	| MNT_SOFTDEP	| \
			MNT_IGNORE	| MNT_EXPUBLIC	| MNT_NOSYMFOLLOW | \
			MNT_GJOURNAL	| MNT_MULTILABEL | MNT_ACLS	| \
			MNT_NFS4ACLS	| MNT_AUTOMOUNTED)

/* Mask of flags that can be updated. */
#define	MNT_UPDATEMASK (MNT_NOSUID	| MNT_NOEXEC	| \
			MNT_SYNCHRONOUS	| MNT_UNION	| MNT_ASYNC	| \
			MNT_NOATIME | \
			MNT_NOSYMFOLLOW	| MNT_IGNORE	| \
			MNT_NOCLUSTERR	| MNT_NOCLUSTERW | MNT_SUIDDIR	| \
			MNT_ACLS	| MNT_USER	| MNT_NFS4ACLS	| \
			MNT_AUTOMOUNTED)

/*
 * External filesystem command modifier flags.
 * Unmount can use the MNT_FORCE flag.
 * XXX: These are not STATES and really should be somewhere else.
 * XXX: MNT_BYFSID collides with MNT_ACLS, but because MNT_ACLS is only used for
 *      mount(2) and MNT_BYFSID is only used for unmount(2) it's harmless.
 */
#define	MNT_UPDATE	0x0000000000010000ULL /* not real mount, just update */
#define	MNT_DELEXPORT	0x0000000000020000ULL /* delete export host lists */
#define	MNT_RELOAD	0x0000000000040000ULL /* reload filesystem data */
#define	MNT_FORCE	0x0000000000080000ULL /* force unmount or readonly */
#define	MNT_SNAPSHOT	0x0000000001000000ULL /* snapshot the filesystem */
#define	MNT_BYFSID	0x0000000008000000ULL /* specify filesystem by ID. */
#define MNT_CMDFLAGS   (MNT_UPDATE	| MNT_DELEXPORT	| MNT_RELOAD	| \
			MNT_FORCE	| MNT_SNAPSHOT	| MNT_BYFSID)
/*
 * Internal filesystem control flags stored in mnt_kern_flag.
 *
 * MNTK_UNMOUNT locks the mount entry so that name lookup cannot proceed
 * past the mount point.  This keeps the subtree stable during mounts
 * and unmounts.
 *
 * MNTK_UNMOUNTF permits filesystems to detect a forced unmount while
 * dounmount() is still waiting to lock the mountpoint. This allows
 * the filesystem to cancel operations that might otherwise deadlock
 * with the unmount attempt (used by NFS).
 *
 * MNTK_NOINSMNTQ is strict subset of MNTK_UNMOUNT. They are separated
 * to allow for failed unmount attempt to restore the syncer vnode for
 * the mount.
 */
#define MNTK_UNMOUNTF	0x00000001	/* forced unmount in progress */
#define MNTK_ASYNC	0x00000002	/* filtered async flag */
#define MNTK_SOFTDEP	0x00000004	/* async disabled by softdep */
#define MNTK_NOINSMNTQ	0x00000008	/* insmntque is not allowed */
#define	MNTK_DRAINING	0x00000010	/* lock draining is happening */
#define	MNTK_REFEXPIRE	0x00000020	/* refcount expiring is happening */
#define MNTK_EXTENDED_SHARED	0x00000040 /* Allow shared locking for more ops */
#define	MNTK_SHARED_WRITES	0x00000080 /* Allow shared locking for writes */
#define	MNTK_NO_IOPF	0x00000100	/* Disallow page faults during reads
					   and writes. Filesystem shall properly
					   handle i/o state on EFAULT. */
#define	MNTK_VGONE_UPPER	0x00000200
#define	MNTK_VGONE_WAITER	0x00000400
#define	MNTK_LOOKUP_EXCL_DOTDOT	0x00000800
#define	MNTK_MARKER		0x00001000
#define	MNTK_UNMAPPED_BUFS	0x00002000
#define	MNTK_USES_BCACHE	0x00004000 /* FS uses the buffer cache. */
#define MNTK_NOASYNC	0x00800000	/* disable async */
#define MNTK_UNMOUNT	0x01000000	/* unmount in progress */
#define	MNTK_MWAIT	0x02000000	/* waiting for unmount to finish */
#define	MNTK_SUSPEND	0x08000000	/* request write suspension */
#define	MNTK_SUSPEND2	0x04000000	/* block secondary writes */
#define	MNTK_SUSPENDED	0x10000000	/* write operations are suspended */
#define	MNTK_UNUSED1	0x20000000
#define MNTK_LOOKUP_SHARED	0x40000000 /* FS supports shared lock lookups */
#define	MNTK_NOKNOTE	0x80000000	/* Don't send KNOTEs from VOP hooks */

#ifdef _KERNEL
static inline int
MNT_SHARED_WRITES(struct mount *mp)
{

	return (mp != NULL && (mp->mnt_kern_flag & MNTK_SHARED_WRITES) != 0);
}

static inline int
MNT_EXTENDED_SHARED(struct mount *mp)
{

	return (mp != NULL && (mp->mnt_kern_flag & MNTK_EXTENDED_SHARED) != 0);
}
#endif

/*
 * Sysctl CTL_VFS definitions.
 *
 * Second level identifier specifies which filesystem. Second level
 * identifier VFS_VFSCONF returns information about all filesystems.
 * Second level identifier VFS_GENERIC is non-terminal.
 */
#define	VFS_VFSCONF		0	/* get configured filesystems */
#define	VFS_GENERIC		0	/* generic filesystem information */
/*
 * Third level identifiers for VFS_GENERIC are given below; third
 * level identifiers for specific filesystems are given in their
 * mount specific header files.
 */
#define VFS_MAXTYPENUM	1	/* int: highest defined filesystem type */
#define VFS_CONF	2	/* struct: vfsconf for filesystem given
				   as next argument */

/*
 * Flags for various system call interfaces.
 *
 * waitfor flags to vfs_sync() and getfsstat()
 */
#define MNT_WAIT	1	/* synchronously wait for I/O to complete */
#define MNT_NOWAIT	2	/* start all I/O, but do not wait for it */
#define MNT_LAZY	3	/* push data not written by filesystem syncer */
#define MNT_SUSPEND	4	/* Suspend file system after sync */

/*
 * Generic file handle
 */
struct fhandle {
	fsid_t	fh_fsid;	/* Filesystem id of mount point */
	struct	fid fh_fid;	/* Filesys specific id */
};
typedef struct fhandle	fhandle_t;

/*
 * Old export arguments without security flavor list
 */
struct oexport_args {
	int	ex_flags;		/* export related flags */
	uid_t	ex_root;		/* mapping for root uid */
	struct	xucred ex_anon;		/* mapping for anonymous user */
	struct	sockaddr *ex_addr;	/* net address to which exported */
	u_char	ex_addrlen;		/* and the net address length */
	struct	sockaddr *ex_mask;	/* mask of valid bits in saddr */
	u_char	ex_masklen;		/* and the smask length */
	char	*ex_indexfile;		/* index file for WebNFS URLs */
};

/*
 * Export arguments for local filesystem mount calls.
 */
#define	MAXSECFLAVORS	5
struct export_args {
	int	ex_flags;		/* export related flags */
	uid_t	ex_root;		/* mapping for root uid */
	struct	xucred ex_anon;		/* mapping for anonymous user */
	struct	sockaddr *ex_addr;	/* net address to which exported */
	u_char	ex_addrlen;		/* and the net address length */
	struct	sockaddr *ex_mask;	/* mask of valid bits in saddr */
	u_char	ex_masklen;		/* and the smask length */
	char	*ex_indexfile;		/* index file for WebNFS URLs */
	int	ex_numsecflavors;	/* security flavor count */
	int	ex_secflavors[MAXSECFLAVORS]; /* list of security flavors */
};

/*
 * Structure holding information for a publicly exported filesystem
 * (WebNFS). Currently the specs allow just for one such filesystem.
 */
struct nfs_public {
	int		np_valid;	/* Do we hold valid information */
	fhandle_t	np_handle;	/* Filehandle for pub fs (internal) */
	struct mount	*np_mount;	/* Mountpoint of exported fs */
	char		*np_index;	/* Index file */
};

/*
 * Filesystem configuration information. One of these exists for each
 * type of filesystem supported by the kernel. These are searched at
 * mount time to identify the requested filesystem.
 *
 * XXX: Never change the first two arguments!
 */
struct vfsconf {
	u_int	vfc_version;		/* ABI version number */
	char	vfc_name[MFSNAMELEN];	/* filesystem type name */
	struct	vfsops *vfc_vfsops;	/* filesystem operations vector */
	int	vfc_typenum;		/* historic filesystem type number */
	int	vfc_refcount;		/* number mounted of this type */
	int	vfc_flags;		/* permanent flags */
	struct	vfsoptdecl *vfc_opts;	/* mount options */
	TAILQ_ENTRY(vfsconf) vfc_list;	/* list of vfscons */
};

/* Userland version of the struct vfsconf. */
struct xvfsconf {
	struct	vfsops *vfc_vfsops;	/* filesystem operations vector */
	char	vfc_name[MFSNAMELEN];	/* filesystem type name */
	int	vfc_typenum;		/* historic filesystem type number */
	int	vfc_refcount;		/* number mounted of this type */
	int	vfc_flags;		/* permanent flags */
	struct	vfsconf *vfc_next;	/* next in list */
};

#ifndef BURN_BRIDGES
struct ovfsconf {
	void	*vfc_vfsops;
	char	vfc_name[32];
	int	vfc_index;
	int	vfc_refcount;
	int	vfc_flags;
};
#endif

/*
 * NB: these flags refer to IMPLEMENTATION properties, not properties of
 * any actual mounts; i.e., it does not make sense to change the flags.
 */
#define	VFCF_STATIC	0x00010000	/* statically compiled into kernel */
#define	VFCF_NETWORK	0x00020000	/* may get data over the network */
#define	VFCF_READONLY	0x00040000	/* writes are not implemented */
#define	VFCF_SYNTHETIC	0x00080000	/* data does not represent real files */
#define	VFCF_LOOPBACK	0x00100000	/* aliases some other mounted FS */
#define	VFCF_UNICODE	0x00200000	/* stores file names as Unicode */
#define	VFCF_JAIL	0x00400000	/* can be mounted from within a jail */
#define	VFCF_DELEGADMIN	0x00800000	/* supports delegated administration */
#define	VFCF_SBDRY	0x01000000	/* defer stop requests */

typedef uint32_t fsctlop_t;

struct vfsidctl {
	int		vc_vers;	/* should be VFSIDCTL_VERS1 (below) */
	fsid_t		vc_fsid;	/* fsid to operate on */
	char		vc_fstypename[MFSNAMELEN];
					/* type of fs 'nfs' or '*' */
	fsctlop_t	vc_op;		/* operation VFS_CTL_* (below) */
	void		*vc_ptr;	/* pointer to data structure */
	size_t		vc_len;		/* sizeof said structure */
	u_int32_t	vc_spare[12];	/* spare (must be zero) */
};

/* vfsidctl API version. */
#define VFS_CTL_VERS1	0x01

/*
 * New style VFS sysctls, do not reuse/conflict with the namespace for
 * private sysctls.
 * All "global" sysctl ops have the 33rd bit set:
 * 0x...1....
 * Private sysctl ops should have the 33rd bit unset.
 */
#define VFS_CTL_QUERY	0x00010001	/* anything wrong? (vfsquery) */
#define VFS_CTL_TIMEO	0x00010002	/* set timeout for vfs notification */
#define VFS_CTL_NOLOCKS	0x00010003	/* disable file locking */

struct vfsquery {
	u_int32_t	vq_flags;
	u_int32_t	vq_spare[31];
};

/* vfsquery flags */
#define VQ_NOTRESP	0x0001	/* server down */
#define VQ_NEEDAUTH	0x0002	/* server bad auth */
#define VQ_LOWDISK	0x0004	/* we're low on space */
#define VQ_MOUNT	0x0008	/* new filesystem arrived */
#define VQ_UNMOUNT	0x0010	/* filesystem has left */
#define VQ_DEAD		0x0020	/* filesystem is dead, needs force unmount */
#define VQ_ASSIST	0x0040	/* filesystem needs assistance from external
				   program */
#define VQ_NOTRESPLOCK	0x0080	/* server lockd down */
#define VQ_FLAG0100	0x0100	/* placeholder */
#define VQ_FLAG0200	0x0200	/* placeholder */
#define VQ_FLAG0400	0x0400	/* placeholder */
#define VQ_FLAG0800	0x0800	/* placeholder */
#define VQ_FLAG1000	0x1000	/* placeholder */
#define VQ_FLAG2000	0x2000	/* placeholder */
#define VQ_FLAG4000	0x4000	/* placeholder */
#define VQ_FLAG8000	0x8000	/* placeholder */

#ifdef _KERNEL
/* Point a sysctl request at a vfsidctl's data. */
#define VCTLTOREQ(vc, req)						\
	do {								\
		(req)->newptr = (vc)->vc_ptr;				\
		(req)->newlen = (vc)->vc_len;				\
		(req)->newidx = 0;					\
	} while (0)
#endif

struct iovec;
struct uio;

#ifdef _KERNEL

/*
 * vfs_busy specific flags and mask.
 */
#define	MBF_NOWAIT	0x01
#define	MBF_MNTLSTLOCK	0x02
#define	MBF_MASK	(MBF_NOWAIT | MBF_MNTLSTLOCK)

#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_MOUNT);
#endif
extern int maxvfsconf;		/* highest defined filesystem type */

TAILQ_HEAD(vfsconfhead, vfsconf);
extern struct vfsconfhead vfsconf;

/*
 * Operations supported on mounted filesystem.
 */
struct mount_args;
struct nameidata;
struct sysctl_req;
struct mntarg;

typedef int vfs_cmount_t(struct mntarg *ma, void *data, uint64_t flags);
typedef int vfs_unmount_t(struct mount *mp, int mntflags);
typedef int vfs_root_t(struct mount *mp, int flags, struct vnode **vpp);
typedef	int vfs_quotactl_t(struct mount *mp, int cmds, uid_t uid, void *arg);
typedef	int vfs_statfs_t(struct mount *mp, struct statfs *sbp);
typedef	int vfs_sync_t(struct mount *mp, int waitfor);
typedef	int vfs_vget_t(struct mount *mp, ino_t ino, int flags,
		    struct vnode **vpp);
typedef	int vfs_fhtovp_t(struct mount *mp, struct fid *fhp,
		    int flags, struct vnode **vpp);
typedef	int vfs_checkexp_t(struct mount *mp, struct sockaddr *nam,
		    int *extflagsp, struct ucred **credanonp,
		    int *numsecflavors, int **secflavors);
typedef	int vfs_init_t(struct vfsconf *);
typedef	int vfs_uninit_t(struct vfsconf *);
typedef	int vfs_extattrctl_t(struct mount *mp, int cmd,
		    struct vnode *filename_vp, int attrnamespace,
		    const char *attrname);
typedef	int vfs_mount_t(struct mount *mp);
typedef int vfs_sysctl_t(struct mount *mp, fsctlop_t op,
		    struct sysctl_req *req);
typedef void vfs_susp_clean_t(struct mount *mp);
typedef void vfs_notify_lowervp_t(struct mount *mp, struct vnode *lowervp);
typedef void vfs_purge_t(struct mount *mp);

struct vfsops {
	vfs_mount_t		*vfs_mount;
	vfs_cmount_t		*vfs_cmount;
	vfs_unmount_t		*vfs_unmount;
	vfs_root_t		*vfs_root;
	vfs_quotactl_t		*vfs_quotactl;
	vfs_statfs_t		*vfs_statfs;
	vfs_sync_t		*vfs_sync;
	vfs_vget_t		*vfs_vget;
	vfs_fhtovp_t		*vfs_fhtovp;
	vfs_checkexp_t		*vfs_checkexp;
	vfs_init_t		*vfs_init;
	vfs_uninit_t		*vfs_uninit;
	vfs_extattrctl_t	*vfs_extattrctl;
	vfs_sysctl_t		*vfs_sysctl;
	vfs_susp_clean_t	*vfs_susp_clean;
	vfs_notify_lowervp_t	*vfs_reclaim_lowervp;
	vfs_notify_lowervp_t	*vfs_unlink_lowervp;
	vfs_purge_t		*vfs_purge;
	vfs_mount_t		*vfs_spare[6];	/* spares for ABI compat */
};

vfs_statfs_t	__vfs_statfs;

#define	VFS_PROLOGUE(MP)	do {					\
	struct mount *mp__;						\
	int _enable_stops;						\
									\
	mp__ = (MP);							\
	_enable_stops = (mp__ != NULL &&				\
	    (mp__->mnt_vfc->vfc_flags & VFCF_SBDRY) && sigdeferstop())

#define	VFS_EPILOGUE(MP)						\
	if (_enable_stops)						\
		sigallowstop();						\
} while (0)

#define	VFS_MOUNT(MP) ({						\
	int _rc;							\
									\
	VFS_PROLOGUE(MP);						\
	_rc = (*(MP)->mnt_op->vfs_mount)(MP);				\
	VFS_EPILOGUE(MP);						\
	_rc; })

#define	VFS_UNMOUNT(MP, FORCE) ({					\
	int _rc;							\
									\
	VFS_PROLOGUE(MP);						\
	_rc = (*(MP)->mnt_op->vfs_unmount)(MP, FORCE);			\
	VFS_EPILOGUE(MP);						\
	_rc; })

#define	VFS_ROOT(MP, FLAGS, VPP) ({					\
	int _rc;							\
									\
	VFS_PROLOGUE(MP);						\
	_rc = (*(MP)->mnt_op->vfs_root)(MP, FLAGS, VPP);		\
	VFS_EPILOGUE(MP);						\
	_rc; })

#define	VFS_QUOTACTL(MP, C, U, A) ({					\
	int _rc;							\
									\
	VFS_PROLOGUE(MP);						\
	_rc = (*(MP)->mnt_op->vfs_quotactl)(MP, C, U, A);		\
	VFS_EPILOGUE(MP);						\
	_rc; })

#define	VFS_STATFS(MP, SBP) ({						\
	int _rc;							\
									\
	VFS_PROLOGUE(MP);						\
	_rc = __vfs_statfs((MP), (SBP));				\
	VFS_EPILOGUE(MP);						\
	_rc; })

#define	VFS_SYNC(MP, WAIT) ({						\
	int _rc;							\
									\
	VFS_PROLOGUE(MP);						\
	_rc = (*(MP)->mnt_op->vfs_sync)(MP, WAIT);			\
	VFS_EPILOGUE(MP);						\
	_rc; })

#define	VFS_VGET(MP, INO, FLAGS, VPP) ({				\
	int _rc;							\
									\
	VFS_PROLOGUE(MP);						\
	_rc = (*(MP)->mnt_op->vfs_vget)(MP, INO, FLAGS, VPP);		\
	VFS_EPILOGUE(MP);						\
	_rc; })

#define	VFS_FHTOVP(MP, FIDP, FLAGS, VPP) ({				\
	int _rc;							\
									\
	VFS_PROLOGUE(MP);						\
	_rc = (*(MP)->mnt_op->vfs_fhtovp)(MP, FIDP, FLAGS, VPP);	\
	VFS_EPILOGUE(MP);						\
	_rc; })

#define	VFS_CHECKEXP(MP, NAM, EXFLG, CRED, NUMSEC, SEC) ({		\
	int _rc;							\
									\
	VFS_PROLOGUE(MP);						\
	_rc = (*(MP)->mnt_op->vfs_checkexp)(MP, NAM, EXFLG, CRED, NUMSEC,\
	    SEC);							\
	VFS_EPILOGUE(MP);						\
	_rc; })

#define	VFS_EXTATTRCTL(MP, C, FN, NS, N) ({				\
	int _rc;							\
									\
	VFS_PROLOGUE(MP);						\
	_rc = (*(MP)->mnt_op->vfs_extattrctl)(MP, C, FN, NS, N);	\
	VFS_EPILOGUE(MP);						\
	_rc; })

#define	VFS_SYSCTL(MP, OP, REQ) ({					\
	int _rc;							\
									\
	VFS_PROLOGUE(MP);						\
	_rc = (*(MP)->mnt_op->vfs_sysctl)(MP, OP, REQ);			\
	VFS_EPILOGUE(MP);						\
	_rc; })

#define	VFS_SUSP_CLEAN(MP) do {						\
	if (*(MP)->mnt_op->vfs_susp_clean != NULL) {			\
		VFS_PROLOGUE(MP);					\
		(*(MP)->mnt_op->vfs_susp_clean)(MP);			\
		VFS_EPILOGUE(MP);					\
	}								\
} while (0)

#define	VFS_RECLAIM_LOWERVP(MP, VP) do {				\
	if (*(MP)->mnt_op->vfs_reclaim_lowervp != NULL) {		\
		VFS_PROLOGUE(MP);					\
		(*(MP)->mnt_op->vfs_reclaim_lowervp)((MP), (VP));	\
		VFS_EPILOGUE(MP);					\
	}								\
} while (0)

#define	VFS_UNLINK_LOWERVP(MP, VP) do {					\
	if (*(MP)->mnt_op->vfs_unlink_lowervp != NULL) {		\
		VFS_PROLOGUE(MP);					\
		(*(MP)->mnt_op->vfs_unlink_lowervp)((MP), (VP));	\
		VFS_EPILOGUE(MP);					\
	}								\
} while (0)

#define	VFS_PURGE(MP) do {						\
	if (*(MP)->mnt_op->vfs_purge != NULL) {				\
		VFS_PROLOGUE(MP);					\
		(*(MP)->mnt_op->vfs_purge)(MP);				\
		VFS_EPILOGUE(MP);					\
	}								\
} while (0)

#define VFS_KNOTE_LOCKED(vp, hint) do					\
{									\
	if (((vp)->v_vflag & VV_NOKNOTE) == 0)				\
		VN_KNOTE((vp), (hint), KNF_LISTLOCKED);			\
} while (0)

#define VFS_KNOTE_UNLOCKED(vp, hint) do					\
{									\
	if (((vp)->v_vflag & VV_NOKNOTE) == 0)				\
		VN_KNOTE((vp), (hint), 0);				\
} while (0)

#define	VFS_NOTIFY_UPPER_RECLAIM	1
#define	VFS_NOTIFY_UPPER_UNLINK		2

#include <sys/module.h>

/*
 * Version numbers.
 */
#define VFS_VERSION_00	0x19660120
#define VFS_VERSION_01	0x20121030
#define VFS_VERSION	VFS_VERSION_01

#define VFS_SET(vfsops, fsname, flags) \
	static struct vfsconf fsname ## _vfsconf = {		\
		.vfc_version = VFS_VERSION,			\
		.vfc_name = #fsname,				\
		.vfc_vfsops = &vfsops,				\
		.vfc_typenum = -1,				\
		.vfc_flags = flags,				\
	};							\
	static moduledata_t fsname ## _mod = {			\
		#fsname,					\
		vfs_modevent,					\
		& fsname ## _vfsconf				\
	};							\
	DECLARE_MODULE(fsname, fsname ## _mod, SI_SUB_VFS, SI_ORDER_MIDDLE)

/*
 * exported vnode operations
 */

int	dounmount(struct mount *, int, struct thread *);

int	kernel_mount(struct mntarg *ma, uint64_t flags);
int	kernel_vmount(int flags, ...);
struct mntarg *mount_arg(struct mntarg *ma, const char *name, const void *val, int len);
struct mntarg *mount_argb(struct mntarg *ma, int flag, const char *name);
struct mntarg *mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...);
struct mntarg *mount_argsu(struct mntarg *ma, const char *name, const void *val, int len);
void	statfs_scale_blocks(struct statfs *sf, long max_size);
struct vfsconf *vfs_byname(const char *);
struct vfsconf *vfs_byname_kld(const char *, struct thread *td, int *);
void	vfs_mount_destroy(struct mount *);
void	vfs_event_signal(fsid_t *, u_int32_t, intptr_t);
void	vfs_freeopts(struct vfsoptlist *opts);
void	vfs_deleteopt(struct vfsoptlist *opts, const char *name);
int	vfs_buildopts(struct uio *auio, struct vfsoptlist **options);
int	vfs_flagopt(struct vfsoptlist *opts, const char *name, uint64_t *w,
	    uint64_t val);
int	vfs_getopt(struct vfsoptlist *, const char *, void **, int *);
int	vfs_getopt_pos(struct vfsoptlist *opts, const char *name);
int	vfs_getopt_size(struct vfsoptlist *opts, const char *name,
	    off_t *value);
char	*vfs_getopts(struct vfsoptlist *, const char *, int *error);
int	vfs_copyopt(struct vfsoptlist *, const char *, void *, int);
int	vfs_filteropt(struct vfsoptlist *, const char **legal);
void	vfs_opterror(struct vfsoptlist *opts, const char *fmt, ...);
int	vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...);
int	vfs_setopt(struct vfsoptlist *opts, const char *name, void *value,
	    int len);
int	vfs_setopt_part(struct vfsoptlist *opts, const char *name, void *value,
	    int len);
int	vfs_setopts(struct vfsoptlist *opts, const char *name,
	    const char *value);
int	vfs_setpublicfs			    /* set publicly exported fs */
	    (struct mount *, struct netexport *, struct export_args *);
void	vfs_msync(struct mount *, int);
int	vfs_busy(struct mount *, int);
int	vfs_export			 /* process mount export info */
	    (struct mount *, struct export_args *);
void	vfs_allocate_syncvnode(struct mount *);
void	vfs_deallocate_syncvnode(struct mount *);
int	vfs_donmount(struct thread *td, uint64_t fsflags,
	    struct uio *fsoptions);
void	vfs_getnewfsid(struct mount *);
struct cdev *vfs_getrootfsid(struct mount *);
struct	mount *vfs_getvfs(fsid_t *);      /* return vfs given fsid */
struct	mount *vfs_busyfs(fsid_t *);
int	vfs_modevent(module_t, int, void *);
void	vfs_mount_error(struct mount *, const char *, ...);
void	vfs_mountroot(void);			/* mount our root filesystem */
void	vfs_mountedfrom(struct mount *, const char *from);
void	vfs_notify_upper(struct vnode *, int);
void	vfs_oexport_conv(const struct oexport_args *oexp,
	    struct export_args *exp);
void	vfs_ref(struct mount *);
void	vfs_rel(struct mount *);
struct mount *vfs_mount_alloc(struct vnode *, struct vfsconf *, const char *,
	    struct ucred *);
int	vfs_suser(struct mount *, struct thread *);
void	vfs_unbusy(struct mount *);
void	vfs_unmountall(void);
extern	TAILQ_HEAD(mntlist, mount) mountlist;	/* mounted filesystem list */
extern	struct mtx mountlist_mtx;
extern	struct nfs_public nfs_pub;
extern	struct sx vfsconf_sx;
#define	vfsconf_lock()		sx_xlock(&vfsconf_sx)
#define	vfsconf_unlock()	sx_xunlock(&vfsconf_sx)
#define	vfsconf_slock()		sx_slock(&vfsconf_sx)
#define	vfsconf_sunlock()	sx_sunlock(&vfsconf_sx)

/*
 * Declarations for these vfs default operations are located in
 * kern/vfs_default.c.  They will be automatically used to replace
 * null entries in VFS ops tables when registering a new filesystem
 * type in the global table.
 */
vfs_root_t		vfs_stdroot;
vfs_quotactl_t		vfs_stdquotactl;
vfs_statfs_t		vfs_stdstatfs;
vfs_sync_t		vfs_stdsync;
vfs_sync_t		vfs_stdnosync;
vfs_vget_t		vfs_stdvget;
vfs_fhtovp_t		vfs_stdfhtovp;
vfs_checkexp_t		vfs_stdcheckexp;
vfs_init_t		vfs_stdinit;
vfs_uninit_t		vfs_stduninit;
vfs_extattrctl_t	vfs_stdextattrctl;
vfs_sysctl_t		vfs_stdsysctl;

void	syncer_suspend(void);
void	syncer_resume(void);

#else /* !_KERNEL */

#include <sys/cdefs.h>

struct stat;

__BEGIN_DECLS
int	fhopen(const struct fhandle *, int);
int	fhstat(const struct fhandle *, struct stat *);
int	fhstatfs(const struct fhandle *, struct statfs *);
int	fstatfs(int, struct statfs *);
int	getfh(const char *, fhandle_t *);
int	getfsstat(struct statfs *, long, int);
int	getmntinfo(struct statfs **, int);
int	lgetfh(const char *, fhandle_t *);
int	mount(const char *, const char *, int, void *);
int	nmount(struct iovec *, unsigned int, int);
int	statfs(const char *, struct statfs *);
int	unmount(const char *, int);

/* C library stuff */
int	getvfsbyname(const char *, struct xvfsconf *);
__END_DECLS

#endif /* _KERNEL */

#endif /* !_SYS_MOUNT_H_ */