/*
 * 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.
 * 3. 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: src/sys/sys/mount.h,v 1.89.2.7 2003/04/04 20:35:57 tegge Exp $
 */

#ifndef _SYS_MOUNT_H_
#define _SYS_MOUNT_H_

#include <sys/cdefs.h>
#include <sys/queue.h>
#include <sys/tree.h>
#include <sys/ucred.h>

#ifndef _KERNEL
#if __BSD_VISIBLE
#include <sys/stat.h>
#endif /* __BSD_VISIBLE */
#endif /* !_KERNEL */

#if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
#ifndef _SYS_LOCK_H_
#include <sys/lock.h>
#endif
#ifndef _SYS_NAMECACHE_H_
#include <sys/namecache.h>
#endif
#ifndef _SYS_STATVFS_H_
#include <sys/statvfs.h>
#endif
#ifndef _SYS_THREAD_H_
#include <sys/thread.h>
#endif
#include <sys/vfs_quota.h>
#include <sys/mplock2.h>
#endif

struct thread;
struct journal;
struct vop_ops;
struct vop_mountctl_args;
struct statvfs;
struct vmntvnodescan_info;

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

#define fsidcmp(a, b) memcmp((a), (b), sizeof(fsid_t))

/*
 * File identifier.  These are unique per filesystem on a single machine.
 *
 * fix_ext is also used by HAMMER.
 */
#define MAXFIDSZ        16

struct fid {
        u_short         fid_len;                /* length of data in bytes */
        u_short         fid_ext;                /* extended data           */
        char            fid_data[MAXFIDSZ];     /* data (variable length) */
} __packed;

/*
 * file system statistics
 */

#define MFSNAMELEN      16      /* length of fs type name, including null */
#define MNAMELEN        80      /* length of buffer for returned name */

struct statfs {
        long    f_spare2;               /* placeholder */
        long    f_bsize;                /* fundamental file system block size */
        long    f_iosize;               /* optimal transfer block size */
        long    f_blocks;               /* total data blocks in file system */
        long    f_bfree;                /* free blocks in fs */
        long    f_bavail;               /* free blocks avail to non-superuser */
        long    f_files;                /* total file nodes in file system */
        long    f_ffree;                /* free file nodes in fs */
        fsid_t  f_fsid;                 /* file system 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[MFSNAMELEN]; /* fs type name */
        char    f_mntonname[MNAMELEN];  /* 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[MNAMELEN];/* mounted filesystem */
        short   f_spares2;              /* unused spare */
        long    f_spare[2];             /* unused spare */
};

#if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)

/*
 * bio_ops are associated with the mount structure and used in conjuction
 * with the b_dep field in a buffer.  Currently softupdates and HAMMER
 * utilize this field.
 *
 * All bio_ops callbacks must be MPSAFE and could be called without
 * the mplock.
 */
struct buf;

struct bio_ops {
        TAILQ_ENTRY(bio_ops) entry;
        void    (*io_start) (struct buf *);
        void    (*io_complete) (struct buf *);
        void    (*io_deallocate) (struct buf *);
        int     (*io_fsync) (struct vnode *);
        int     (*io_sync) (struct mount *);
        void    (*io_movedeps) (struct buf *, struct buf *);
        int     (*io_countdeps) (struct buf *, int);
        int     (*io_checkread) (struct buf *);
        int     (*io_checkwrite) (struct buf *);
};

#endif

/*
 * vfs quota accounting
 *
 * uids and gids often come in contiguous blocks; use a small linear
 * array as the basic in-memory accounting allocation unit
 */
#define ACCT_CHUNK_BITS 5
#define ACCT_CHUNK_NIDS (1<<ACCT_CHUNK_BITS)
#define ACCT_CHUNK_MASK (ACCT_CHUNK_NIDS - 1)

struct ac_counters {
        uint64_t space;
        uint64_t limit;
};

struct ac_unode {
        RB_ENTRY(ac_unode)      rb_entry;
        uid_t                   left_bits;
        struct ac_counters      uid_chunk[ACCT_CHUNK_NIDS];
};

struct ac_gnode {
        RB_ENTRY(ac_gnode)      rb_entry;
        gid_t                   left_bits;
        struct ac_counters      gid_chunk[ACCT_CHUNK_NIDS];
};

#if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)

struct vfs_acct {
        RB_HEAD(ac_utree,ac_unode)      ac_uroot;
        RB_HEAD(ac_gtree,ac_gnode)      ac_groot;
        uint64_t                        ac_bytes;       /* total bytes used */
        uint64_t                        ac_limit;
        struct spinlock                 ac_spin;        /* protective spinlock */
};


/*
 * Structure per mounted file system.  Each mounted file system has an
 * array of operations and an instance record.  The file systems are
 * put on a doubly linked list.
 *
 * NOTE: mnt_nvnodelist and mnt_reservedvnlist.  At the moment vnodes
 * are linked into mnt_nvnodelist.  At some point in the near future the
 * vnode list will be split into a 'dirty' and 'clean' list. mnt_nvnodelist
 * will become the dirty list and mnt_reservedvnlist will become the 'clean'
 * list.  Filesystem kld's syncing code should remain compatible since
 * they only need to scan the dirty vnode list (nvnodelist -> dirtyvnodelist).
 *
 * NOTE: All VFSs must at least populate mnt_vn_ops or those VOP ops that
 * only take namecache pointers will not be able to find their operations
 * vector via namecache->nc_mount.
 *
 * MPSAFE NOTES: mnt_lock interlocks mounting and unmounting operations.
 *
 *               mnt_token interlocks operations which adjust the mount
 *               structure and will also be held through VFS operations
 *               for VFSes not flagged MPSAFE.
 *
 *               The VFS should pre-set VFCF_MPSAFE in the VFS_SET() to
 *               avoid use of the mplock during mounting.  This will also
 *               cause MNTK_ALL_MPSAFE to be set in mnt_kern_flags.  If the
 *               VFS does not set VFCF_MPSAFE then it can set individual
 *               MNTK_*_MPSAFE flags in mnt_kern_flags.
 */
TAILQ_HEAD(vnodelst, vnode);
TAILQ_HEAD(journallst, journal);

struct mount {
        TAILQ_ENTRY(mount) mnt_list;            /* mount list */
        struct vfsops   *mnt_op;                /* operations on fs */
        struct vfsconf  *mnt_vfc;               /* configuration info */
        u_int           mnt_namecache_gen;      /* ++ to clear negative hits */
        u_int           mnt_pbuf_count;         /* pbuf usage limit */
        struct vnode    *mnt_syncer;            /* syncer vnode */
        struct syncer_ctx *mnt_syncer_ctx;      /* syncer process context */
        struct vnodelst mnt_nvnodelist;         /* list of vnodes this mount */
        TAILQ_HEAD(,vmntvnodescan_info) mnt_vnodescan_list;
        struct lock     mnt_lock;               /* mount structure lock */
        int             mnt_flag;               /* flags shared with user */
        int             mnt_kern_flag;          /* kernel only flags */
        int             mnt_maxsymlinklen;      /* max size of short symlink */
        struct statfs   mnt_stat;               /* cache of filesystem stats */
        struct statvfs  mnt_vstat;              /* extended stats */
        qaddr_t         mnt_data;               /* private data */
        time_t          mnt_time;               /* last time written*/
        u_int           mnt_iosize_max;         /* max IO request size */
        struct vnodelst mnt_reservedvnlist;     /* (future) dirty vnode list */
        int             mnt_nvnodelistsize;     /* # of vnodes on this mount */

        /*
         * ops vectors have a fixed stacking order.  All primary calls run
         * through mnt_vn_ops.  This field is typically assigned to
         * mnt_vn_norm_ops.  If journaling has been enabled this field is
         * usually assigned to mnt_vn_journal_ops.
         */
        struct vop_ops  *mnt_vn_use_ops;        /* current ops set */

        struct vop_ops  *mnt_vn_coherency_ops;  /* cache coherency ops */
        struct vop_ops  *mnt_vn_journal_ops;    /* journaling ops */
        struct vop_ops  *mnt_vn_norm_ops;       /* for use by the VFS */
        struct vop_ops  *mnt_vn_spec_ops;       /* for use by the VFS */
        struct vop_ops  *mnt_vn_fifo_ops;       /* for use by the VFS */
        struct nchandle mnt_ncmountpt;          /* mount point */
        struct nchandle mnt_ncmounton;          /* mounted on */
        char            mnt_pad[16];            /* (try to cache-align refs) */
        struct ucred    *mnt_cred;              /* for cr_prison */
        int             mnt_refs;               /* nchandle references */
        int             mnt_hold;               /* prevent kfree */
        struct lwkt_token mnt_token;            /* token lock if not MPSAFE */
        struct journallst mnt_jlist;            /* list of active journals */
        u_int8_t        *mnt_jbitmap;           /* streamid bitmap */
        int16_t         mnt_streamid;           /* last streamid */

        struct bio_ops  *mnt_bioops;            /* BIO ops (hammer, softupd) */
        struct lock     mnt_renlock;            /* rename directory lock */

        struct vfs_acct mnt_acct;               /* vfs space accounting */
        RB_ENTRY(mount) mnt_node;               /* mnt_stat.f_fsid */
};

#endif /* _KERNEL || _KERNEL_STRUCTURES */

/*
 * User specifiable flags.
 */
#define MNT_RDONLY      0x00000001      /* read only filesystem */
#define MNT_SYNCHRONOUS 0x00000002      /* file system written synchronously */
#define MNT_NOEXEC      0x00000004      /* can't exec from filesystem */
#define MNT_NOSUID      0x00000008      /* don't honor setuid bits on fs */
#define MNT_NODEV       0x00000010      /* don't interpret special files */
#define MNT_AUTOMOUNTED 0x00000020      /* mounted by automountd(8) */
#define MNT_ASYNC       0x00000040      /* file system written asynchronously */
#define MNT_SUIDDIR     0x00100000      /* special handling of SUID on dirs */
#define MNT_SOFTDEP     0x00200000      /* soft updates being done */
#define MNT_NOSYMFOLLOW 0x00400000      /* do not follow symlinks */
#define MNT_TRIM        0x01000000      /* Enable online FS trimming */
#define MNT_NOATIME     0x10000000      /* disable update of file access time */
#define MNT_NOCLUSTERR  0x40000000      /* disable cluster read */
#define MNT_NOCLUSTERW  0x80000000      /* disable cluster write */

/*
 * NFS export related mount flags.
 */
#define MNT_EXRDONLY    0x00000080      /* exported read only */
#define MNT_EXPORTED    0x00000100      /* file system is exported */
#define MNT_DEFEXPORTED 0x00000200      /* exported to the world */
#define MNT_EXPORTANON  0x00000400      /* use anon uid mapping for everyone */
#define MNT_EXKERB      0x00000800      /* exported with Kerberos uid mapping */
#define MNT_EXPUBLIC    0x20000000      /* 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       0x00001000      /* filesystem is stored locally */
#define MNT_QUOTA       0x00002000      /* quotas are enabled on filesystem */
#define MNT_ROOTFS      0x00004000      /* identifies the root filesystem */
#define MNT_USER        0x00008000      /* mounted by a user */
#define MNT_IGNORE      0x00800000      /* 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_NODEV                     | \
                        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_NOSYMFOLLOW | MNT_EXPUBLIC| \
                        MNT_TRIM        | 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.
 */
#define MNT_UPDATE      0x00010000      /* not a real mount, just an update */
#define MNT_DELEXPORT   0x00020000      /* delete export host lists */
#define MNT_RELOAD      0x00040000      /* reload filesystem data */
#define MNT_FORCE       0x00080000      /* force unmount or readonly change */
#define MNT_CMDFLAGS    (MNT_UPDATE|MNT_DELEXPORT|MNT_RELOAD|MNT_FORCE)
/*
 * 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_NOSTKMNT prevents mounting another filesystem inside the flagged one.
 */
#define MNTK_UNMOUNTF   0x00000001      /* forced unmount in progress */
#define MNTK_QUICKHALT  0x00008000      /* quick unmount on halt */
#define MNTK_MPSAFE     0x00010000      /* call vops without mnt_token lock */
#define MNTK_RD_MPSAFE  0x00020000      /* vop_read is MPSAFE */
#define MNTK_WR_MPSAFE  0x00040000      /* vop_write is MPSAFE */
#define MNTK_GA_MPSAFE  0x00080000      /* vop_getattr is MPSAFE */
#define MNTK_IN_MPSAFE  0x00100000      /* vop_inactive is MPSAFE */
#define MNTK_SG_MPSAFE  0x00200000      /* vop_strategy is MPSAFE */
#define MNTK_NCALIASED  0x00800000      /* namecached aliased */
#define MNTK_UNMOUNT    0x01000000      /* unmount in progress */
#define MNTK_MWAIT      0x02000000      /* waiting for unmount to finish */
#define MNTK_WANTRDWR   0x04000000      /* upgrade to read/write requested */
#define MNTK_NOSTKMNT   0x10000000      /* no stacked mount point allowed */
#define MNTK_NOMSYNC    0x20000000      /* used by tmpfs */
#define MNTK_THR_SYNC   0x40000000      /* fs sync thread requested */
#define MNTK_ST_MPSAFE  0x80000000      /* (mfs) vfs_start is MPSAFE */

#define MNTK_ALL_MPSAFE (MNTK_MPSAFE | MNTK_RD_MPSAFE | MNTK_WR_MPSAFE | \
                         MNTK_GA_MPSAFE | MNTK_IN_MPSAFE | MNTK_SG_MPSAFE | \
                         MNTK_ST_MPSAFE)

/*
 * mountlist_*() defines
 */
#define MNTSCAN_FORWARD         0x0001
#define MNTSCAN_REVERSE         0x0002
#define MNTSCAN_NOBUSY          0x0004
#define MNTSCAN_NOUNLOCK        0x0008

#define MNTINS_FIRST            0x0001
#define MNTINS_LAST             0x0002

/*
 * 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 */

/*
 * VFS MPLOCK helper.
 *
 * We have to cache the supplied mp because in certain situations
 * the related vnode might go away across the use case (vop_strategy()).
 */
#define VFS_MPLOCK_DECLARE      struct mount *xlock_mp

#define VFS_MPLOCK(mp)          VFS_MPLOCK_FLAG(mp, MNTK_MPSAFE)

#define VFS_MPLOCK_FLAG(mp, flag)                                       \
                do {                                                    \
                        if (mp->mnt_kern_flag & flag) {                 \
                                xlock_mp = NULL;                        \
                        } else {                                        \
                                xlock_mp = (mp);                        \
                                get_mplock();   /* TEMPORARY */         \
                                lwkt_gettoken(&xlock_mp->mnt_token);    \
                        }                                               \
                } while(0)

#define VFS_MPUNLOCK()                                          \
                do {                                                    \
                        if (xlock_mp) {                                 \
                                lwkt_reltoken(&xlock_mp->mnt_token);    \
                                rel_mplock();   /* TEMPORARY */         \
                        }                                               \
                } while(0)

/*
 * Flags for various system call interfaces.
 *
 * waitfor flags to vfs_sync() and getfsstat()
 */
#define MNT_WAIT        0x0001  /* synchronously wait for I/O to complete */
#define MNT_NOWAIT      0x0002  /* start all I/O, but do not wait for it */
#define MNT_LAZY        0x0004  /* be lazy and do not necessarily push it all */

#define VOP_FSYNC_SYSCALL       0x0001  /* from system call */

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

/*
 * Export arguments for local filesystem mount calls.
 */
struct export_args {
        int     ex_flags;               /* export related flags */
        uid_t   ex_root;                /* mapping for root uid */
        struct  ucred ex_anon;          /* mapping for anonymous user */
        struct  sockaddr *ex_addr;      /* net address to which exported */
        int     ex_addrlen;             /* and the net address length */
        struct  sockaddr *ex_mask;      /* mask of valid bits in saddr */
        int     ex_masklen;             /* and the smask length */
        char    *ex_indexfile;          /* index file for WebNFS URLs */
};

/*
 * 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.
 */
struct vfsconf {
        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 */
        STAILQ_ENTRY(vfsconf) vfc_next; /* next in list */
};

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

/*
 * 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_MPSAFE     0x00400000      /* VFS is fully MPSAFE */

/* 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

#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_MOUNT);
#endif
extern int nfs_mount_type;      /* vfc_typenum for nfs, or -1 */

struct vfsconf *vfsconf_find_by_name(const char *);
struct vfsconf *vfsconf_find_by_typenum(int);
int vfsconf_get_maxtypenum(void);
int vfsconf_each(int (*)(struct vfsconf *, void *), void *);

#endif

#if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)

TAILQ_HEAD(mntlist, mount);     /* struct mntlist */

/*
 * Operations supported on mounted file system.
 */
struct nlookupdata;
struct mbuf;

typedef int vfs_mount_t(struct mount *mp, char *path, caddr_t data,
                                    struct ucred *cred);
typedef int vfs_start_t(struct mount *mp, int flags);
typedef int vfs_unmount_t(struct mount *mp, int mntflags);
typedef int vfs_root_t(struct mount *mp, struct vnode **vpp);
typedef int vfs_quotactl_t(struct mount *mp, int cmds, uid_t uid, caddr_t arg,
                                    struct ucred *cred);
typedef int vfs_statfs_t(struct mount *mp, struct statfs *sbp,
                                    struct ucred *cred);
typedef int vfs_statvfs_t(struct mount *mp, struct statvfs *sbp,
                                    struct ucred *cred);
typedef int vfs_sync_t(struct mount *mp, int waitfor);
typedef int vfs_vget_t(struct mount *mp, struct vnode *dvp,
                                    ino_t ino, struct vnode **vpp);
typedef int vfs_fhtovp_t(struct mount *mp, struct vnode *rootvp,
                                    struct fid *fhp, struct vnode **vpp);
typedef int vfs_checkexp_t(struct mount *mp, struct sockaddr *nam,
                                    int *extflagsp, struct ucred **credanonp);
typedef int vfs_vptofh_t(struct vnode *vp, struct fid *fhp);
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 *vp,
                    int attrnamespace, const char *attrname,
                    struct ucred *cred);
typedef int vfs_acinit_t(struct mount *mp);
typedef void vfs_acdone_t(struct mount *mp);
typedef void vfs_account_t(struct mount *mp,
                        uid_t uid, gid_t gid, int64_t delta);
typedef void vfs_ncpgen_set_t(struct mount *mp, struct namecache *ncp);
typedef int vfs_ncpgen_test_t(struct mount *mp, struct namecache *ncp);
typedef int vfs_modifying_t(struct mount *mp);

int vfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred);
int vfs_start(struct mount *mp, int flags);
int vfs_unmount(struct mount *mp, int mntflags);
int vfs_root(struct mount *mp, struct vnode **vpp);
int vfs_quotactl(struct mount *mp, int cmds, uid_t uid, caddr_t arg,
                                struct ucred *cred);
int vfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred);
int vfs_statvfs(struct mount *mp, struct statvfs *sbp, struct ucred *cred);
int vfs_sync(struct mount *mp, int waitfor);
int vfs_vget(struct mount *mp, struct vnode *dvp,
                                ino_t ino, struct vnode **vpp);
int vfs_fhtovp(struct mount *mp, struct vnode *rootvp,
                                struct fid *fhp, struct vnode **vpp);
int vfs_checkexp(struct mount *mp, struct sockaddr *nam,
                                int *extflagsp, struct ucred **credanonp);
int vfs_vptofh(struct vnode *vp, struct fid *fhp);
int vfs_init(struct vfsconf *vfc);
int vfs_uninit(struct vfsconf *vfc, struct vfsconf *vfsp);
int vfs_extattrctl(struct mount *mp, int cmd, struct vnode *vp,
                    int attrnamespace, const char *attrname,
                    struct ucred *cred);
int vfs_modifying(struct mount *mp);

struct vfsops {
        long            vfs_flags;
        vfs_mount_t     *vfs_mount;
        vfs_start_t     *vfs_start;
        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_vptofh_t    *vfs_vptofh;
        vfs_init_t      *vfs_init;
        vfs_uninit_t    *vfs_uninit;
        vfs_extattrctl_t *vfs_extattrctl;
        vfs_statvfs_t   *vfs_statvfs;
        vfs_acinit_t    *vfs_acinit;
        vfs_acdone_t    *vfs_acdone;
        vfs_account_t   *vfs_account;
        vfs_ncpgen_set_t        *vfs_ncpgen_set;
        vfs_ncpgen_test_t       *vfs_ncpgen_test;
        vfs_modifying_t *vfs_modifying;
};

#define VFSOPSF_NOSYNCERTHR     0x00000001

#define VFS_MOUNT(MP, PATH, DATA, CRED)         \
        vfs_mount(MP, PATH, DATA, CRED)
#define VFS_START(MP, FLAGS)                    \
        vfs_start(MP, FLAGS)
#define VFS_UNMOUNT(MP, FORCE)                  \
        vfs_unmount(MP, FORCE)
#define VFS_ROOT(MP, VPP)                       \
        vfs_root(MP, VPP)
#define VFS_QUOTACTL(MP, C, U, A, CRED)         \
        vfs_quotactl(MP, C, U, A, CRED)
#define VFS_STATFS(MP, SBP, CRED)               \
        vfs_statfs(MP, SBP, CRED)
#define VFS_STATVFS(MP, SBP, CRED)              \
        vfs_statvfs(MP, SBP, CRED)
#define VFS_SYNC(MP, WAIT)                      \
        vfs_sync(MP, WAIT)
#define VFS_VGET(MP, DVP, INO, VPP)             \
        vfs_vget(MP, DVP, INO, VPP)
#define VFS_FHTOVP(MP, ROOTVP, FIDP, VPP)       \
        vfs_fhtovp(MP, ROOTVP, FIDP, VPP)
#define VFS_VPTOFH(VP, FIDP)                    \
        vfs_vptofh(VP, FIDP)
#define VFS_CHECKEXP(MP, NAM, EXFLG, CRED)      \
        vfs_checkexp(MP, NAM, EXFLG, CRED)
#define VFS_EXTATTRCTL(MP, C, FVP, NS, N, CRED) \
        vfs_extattrctl(MP, C, FVP, NS, N, CRED)
#define VFS_ACCOUNT(MP, U, G, D) \
        if ((MP->mnt_op->vfs_account != NULL) && (D != 0)) \
                MP->mnt_op->vfs_account(MP, U, G, D);
#define VFS_ACINIT(MP, ERROR) \
        if (vfs_quota_enabled && MP->mnt_op->vfs_acinit != NULL) \
                ERROR = MP->mnt_op->vfs_acinit(MP);
#define VFS_ACDONE(MP) \
        if (vfs_quota_enabled && MP->mnt_op->vfs_acdone != NULL) \
                MP->mnt_op->vfs_acdone(MP);
#define VFS_NCPGEN_SET(MP, NCP) \
        MP->mnt_op->vfs_ncpgen_set(MP, NCP)
#define VFS_NCPGEN_TEST(MP, NCP) \
        MP->mnt_op->vfs_ncpgen_test(MP, NCP)
#define VFS_MODIFYING(MP) \
        MP->mnt_op->vfs_modifying(MP)

#endif

#ifdef _KERNEL

#include <sys/module.h>

#define VFS_SET(vfsops, fsname, flags) \
        static struct vfsconf fsname ## _vfsconf = {            \
                &vfsops,                                        \
                #fsname,                                        \
                -1,                                             \
                0,                                              \
                flags,                                          \
                { NULL },                                       \
        };                                                      \
        static moduledata_t fsname ## _mod = {                  \
                #fsname,                                        \
                vfs_modevent,                                   \
                & fsname ## _vfsconf                            \
        };                                                      \
        DECLARE_MODULE(fsname, fsname ## _mod, SI_SUB_VFS, SI_ORDER_MIDDLE)

#endif

#if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)

#include <net/radix.h>

/*
 * Network address lookup element
 */
struct netcred {
        struct  radix_node netc_rnodes[2];
        int     netc_exflags;
        struct  ucred netc_anon;
};

/*
 * Network export information
 */
struct netexport {
        struct  netcred ne_defexported;         /* Default export */
        struct  radix_node_head *ne_inethead;   /* IPv4 radix */
        struct  radix_node_head *ne_inet6head;  /* IPv6 radix */
        struct  radix_node_head *ne_maskhead;   /* Shared mask radix */
};
#define NE_LOCK(nep)            lwkt_getpooltoken(nep)
#define NE_UNLOCK(nep)          lwkt_relpooltoken(nep)
#define NE_ASSERT_LOCKED(nep)   \
    ASSERT_LWKT_TOKEN_HELD(lwkt_token_pool_lookup(nep))

#endif

#ifdef _KERNEL
/*
 * exported vnode operations
 */
void    mount_hold(struct mount *);
void    mount_drop(struct mount *);
int     dounmount (struct mount *, int, int);
int     vfs_setpublicfs                     /* set publicly exported fs */
          (struct mount *, struct netexport *, const struct export_args *);
int     vfs_lock (struct mount *);         /* lock a vfs */
void    vfs_msync (struct mount *, int);
void    vfs_unlock (struct mount *);       /* unlock a vfs */
int     vfs_busy (struct mount *, int);
int     vfs_export                          /* process mount export info */
          (struct mount *, struct netexport *, const struct export_args *);
struct  netcred *vfs_export_lookup          /* lookup host in fs export list */
          (struct mount *, struct netexport *, struct sockaddr *);
int     vfs_allocate_syncvnode (struct mount *);
void    vfs_getnewfsid (struct mount *);
void    vfs_setfsid(struct mount *mp, fsid_t *template);
cdev_t  vfs_getrootfsid (struct mount *);
struct  mount *vfs_getvfs (fsid_t *);      /* return vfs given fsid */
int     vfs_modevent (module_t, int, void *);
int     vfs_mountedon (struct vnode *);    /* is a vfs mounted on vp */
int     vfs_rootmountalloc (char *, char *, struct mount **);
void    vfs_unbusy (struct mount *);
void    vfs_unmountall (int halting);
int     vfs_register (struct vfsconf *);
int     vfs_unregister (struct vfsconf *);
extern  struct nfs_public nfs_pub;

/* 
 * Declarations for these vfs default operations are located in 
 * kern/vfs_default.c, they should be used instead of making "dummy" 
 * functions or casting entries in the VFS op table to "enopnotsupp()".
 */ 
vfs_start_t     vfs_stdstart;
vfs_root_t      vfs_stdroot;
vfs_quotactl_t  vfs_stdquotactl;
vfs_statfs_t    vfs_stdstatfs;
vfs_statvfs_t   vfs_stdstatvfs;
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_vptofh_t    vfs_stdvptofh;
vfs_init_t      vfs_stdinit;
vfs_uninit_t    vfs_stduninit;
vfs_extattrctl_t vfs_stdextattrctl;
vfs_acinit_t    vfs_stdac_init;
vfs_acdone_t    vfs_stdac_done;
vfs_account_t   vfs_stdaccount;
vfs_account_t   vfs_noaccount;
vfs_ncpgen_set_t        vfs_stdncpgen_set;
vfs_ncpgen_test_t       vfs_stdncpgen_test;
vfs_modifying_t vfs_stdmodifying;

struct vop_access_args;
int vop_helper_access(struct vop_access_args *ap, uid_t ino_uid, gid_t ino_gid,
                        mode_t ino_mode, u_int32_t ino_flags);
int vop_helper_setattr_flags(u_int32_t *ino_flags, u_int32_t vaflags,
                        uid_t uid, struct ucred *cred);
uid_t vop_helper_create_uid(struct mount *mp, mode_t dmode, uid_t duid,
                        struct ucred *cred, mode_t *modep);
int vop_helper_chmod(struct vnode *vp, mode_t new_mode, struct ucred *cred,
                        uid_t cur_uid, gid_t cur_gid, mode_t *cur_modep);
int vop_helper_chown(struct vnode *vp, uid_t new_uid, gid_t new_gid,
                        struct ucred *cred,
                        uid_t *cur_uidp, gid_t *cur_gidp, mode_t *cur_modep);
int vop_helper_read_shortcut(struct vop_read_args *ap);

void    add_bio_ops(struct bio_ops *ops);
void    rem_bio_ops(struct bio_ops *ops);

int     journal_mountctl(struct vop_mountctl_args *ap);
void    journal_remove_all_journals(struct mount *mp, int flags);

void    mountlist_insert(struct mount *, int);
int     mountlist_interlock(int (*callback)(struct mount *), struct mount *);
struct mount *mountlist_boot_getfirst(void);
void    mountlist_remove(struct mount *mp);
int     mountlist_exists(struct mount *mp);
int     mountlist_scan(int (*callback)(struct mount *, void *), void *, int);
struct mount *mount_get_by_nc(struct namecache *ncp);
#else /* !_KERNEL */

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

/* C library stuff */
void    endvfsent (void);
struct  ovfsconf *getvfsbyname (const char *);
struct  ovfsconf *getvfsbytype (int);
struct  ovfsconf *getvfsent (void);
#define getvfsbyname    new_getvfsbyname
int     new_getvfsbyname (const char *, struct vfsconf *);
void    setvfsent (int);
int     vfsisloadable (const char *);
int     vfsload (const char *);
__END_DECLS

#endif /* _KERNEL */

#endif /* !_SYS_MOUNT_H_ */