mount.h

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

/*
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 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	8.13 (Berkeley) 3/27/94
 *	$Id: mount.h,v 1.1 1998/08/19 21:32:26 joel Exp $
 */

#ifndef _SYS_MOUNT_H_
#define _SYS_MOUNT_H_

#ifndef KERNEL
#include <sys/ucred.h>
#endif
#include <sys/queue.h>

typedef struct fsid { long val[2]; } fsid_t;	/* file system 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_reserved;		/* force longword alignment */
	char		fid_data[MAXFIDSZ];	/* data (variable length) */
};

/*
 * file system statistics
 */

#define MNAMELEN 90	/* 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 (see below) */
	int	f_flags;		/* copy of mount flags */
	long	f_spare[6];		/* spare for later */
	char	f_mntonname[MNAMELEN];	/* directory on which mounted */
	char	f_mntfromname[MNAMELEN];/* mounted filesystem */
};

/*
 * File system types.
 */
#define	MOUNT_NONE	0
#define	MOUNT_UFS	1	/* Fast Filesystem */
#define	MOUNT_NFS	2	/* Sun-compatible Network Filesystem */
#define	MOUNT_MFS	3	/* Memory-based Filesystem */
#define	MOUNT_MSDOS	4	/* MS/DOS Filesystem */
#define	MOUNT_LFS	5	/* Log-based Filesystem */
#define	MOUNT_LOFS	6	/* Loopback Filesystem */
#define	MOUNT_FDESC	7	/* File Descriptor Filesystem */
#define	MOUNT_PORTAL	8	/* Portal Filesystem */
#define MOUNT_NULL	9	/* Minimal Filesystem Layer */
#define MOUNT_UMAP	10	/* User/Group Identifier Remapping Filesystem */
#define MOUNT_KERNFS	11	/* Kernel Information Filesystem */
#define MOUNT_PROCFS	12	/* /proc Filesystem */
#define MOUNT_AFS	13	/* Andrew Filesystem */
#define MOUNT_CD9660	14	/* ISO9660 (aka CDROM) Filesystem */
#define MOUNT_UNION	15	/* Union (translucent) Filesystem */
#define MOUNT_DEVFS	16	/* existing device Filesystem */
#define	MOUNT_EXT2FS	17	/* Linux EXT2FS */
#define MOUNT_TFS	18	/* Netcon Novell filesystem */
#define	MOUNT_CFS	19	/* Coda filesystem */
#define	MOUNT_MAXTYPE	19

#define INITMOUNTNAMES { \
	"none",		/*  0 MOUNT_NONE */ \
	"ufs",		/*  1 MOUNT_UFS */ \
	"nfs",		/*  2 MOUNT_NFS */ \
	"mfs",		/*  3 MOUNT_MFS */ \
	"msdos",	/*  4 MOUNT_MSDOS */ \
	"lfs",		/*  5 MOUNT_LFS */ \
	"lofs",		/*  6 MOUNT_LOFS */ \
	"fdesc",	/*  7 MOUNT_FDESC */ \
	"portal",	/*  8 MOUNT_PORTAL */ \
	"null",		/*  9 MOUNT_NULL */ \
	"umap",		/* 10 MOUNT_UMAP */ \
	"kernfs",	/* 11 MOUNT_KERNFS */ \
	"procfs",	/* 12 MOUNT_PROCFS */ \
	"afs",		/* 13 MOUNT_AFS */ \
	"cd9660",	/* 14 MOUNT_CD9660 */ \
	"union",	/* 15 MOUNT_UNION */ \
	"devfs",	/* 16 MOUNT_DEVFS */ \
	"ext2fs",	/* 17 MOUNT_EXT2FS */ \
	"tfs",		/* 18 MOUNT_TFS */ \
	"cfs",		/* 19 MOUNT_CFS */ \
	0,		/* 20 MOUNT_SPARE */ \
}

/*
 * 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.
 */
LIST_HEAD(vnodelst, vnode);

struct mount {
	CIRCLEQ_ENTRY(mount) mnt_list;		/* mount list */
	struct vfsops	*mnt_op;		/* operations on fs */
	struct vfsconf	*mnt_vfc;		/* configuration info */
	struct vnode	*mnt_vnodecovered;	/* vnode we mounted on */
	struct vnodelst	mnt_vnodelist;		/* list of vnodes this mount */
	int		mnt_flag;		/* flags */
	int		mnt_maxsymlinklen;	/* max size of short symlink */
	struct statfs	mnt_stat;		/* cache of filesystem stats */
	qaddr_t		mnt_data;		/* private data */
/*	struct vfsconf	*mnt_vfc; */		/* configuration info */
	time_t		mnt_time;		/* last time written*/
};

/*
 * Mount flags.
 *
 * Unmount uses MNT_FORCE flag.
 */
#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_UNION	0x00000020	/* union with underlying filesystem */
#define	MNT_ASYNC	0x00000040	/* file system written asynchronously */
#define	MNT_NOATIME	0x10000000	/* Disable update of file access times */

/*
 * exported 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 */

/*
 * Flags set by internal operations.
 */
#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 */

/*
 * Mask of flags that are visible to statfs()
 */
#define	MNT_VISFLAGMASK	(MNT_RDONLY|MNT_SYNCHRONOUS|MNT_NOEXEC|MNT_NOSUID| \
			 MNT_NODEV|MNT_UNION|MNT_ASYNC|MNT_EXRDONLY|MNT_EXPORTED| \
			 MNT_DEFEXPORTED|MNT_EXPORTANON|MNT_EXKERB|MNT_LOCAL| \
			 MNT_QUOTA|MNT_ROOTFS|MNT_USER|MNT_NOATIME)

/*
 * filesystem control flags.
 *
 * MNT_MLOCK lock the mount entry so that name lookup cannot proceed
 * past the mount point.  This keeps the subtree stable during mounts
 * and unmounts.
 */
#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_MLOCK	0x00100000	/* lock so that subtree is stable */
#define	MNT_MWAIT	0x00200000	/* someone is waiting for lock */
#define MNT_MPBUSY	0x00400000	/* scan of mount point in progress */
#define MNT_MPWANT	0x00800000	/* waiting for mount point */
#define MNT_UNMOUNT	0x01000000	/* unmount in progress */
#define MNT_WANTRDWR	0x02000000	/* want upgrade to read/write */

/*
 * used to get configured filesystems information
 */
#define VFS_MAXNAMELEN 32
struct vfsconf {
	void *vfc_vfsops;
	char vfc_name[VFS_MAXNAMELEN];
	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	0x00000001	/* statically compiled into kernel */
#define	VFCF_NETWORK	0x00000002	/* may get data over the network */
#define	VFCF_READONLY	0x00000004	/* writes are not implemented */
#define VFCF_SYNTHETIC	0x00000008	/* data does not represent real files */
#define	VFCF_LOOPBACK	0x00000010	/* aliases some other mounted FS */
#define	VFCF_UNICODE	0x00000020	/* stores file names as Unicode*/

/*
 * Operations supported on mounted file system.
 */
#ifdef KERNEL

extern	int	doforce;	/* Flag to permit forcible unmounting. */
extern struct vfsconf void_vfsconf;
extern struct vfsconf *vfsconf[];

#ifdef __STDC__
struct nameidata;
struct mbuf;
#endif

struct vfsops {
	int	(*vfs_mount)	__P((struct mount *mp, char *path, caddr_t data,
				    struct nameidata *ndp, struct proc *p));
	int	(*vfs_start)	__P((struct mount *mp, int flags,
				    struct proc *p));
	int	(*vfs_unmount)	__P((struct mount *mp, int mntflags,
				    struct proc *p));
	int	(*vfs_root)	__P((struct mount *mp, struct vnode **vpp));
	int	(*vfs_quotactl)	__P((struct mount *mp, int cmds, uid_t uid,
				    caddr_t arg, struct proc *p));
	int	(*vfs_statfs)	__P((struct mount *mp, struct statfs *sbp,
				    struct proc *p));
	int	(*vfs_sync)	__P((struct mount *mp, int waitfor,
				    struct ucred *cred, struct proc *p));
	int	(*vfs_vget)	__P((struct mount *mp, ino_t ino,
				    struct vnode **vpp));
	int	(*vfs_fhtovp)	__P((struct mount *mp, struct fid *fhp,
				    struct mbuf *nam, struct vnode **vpp,
				    int *exflagsp, struct ucred **credanonp));
	int	(*vfs_vptofh)	__P((struct vnode *vp, struct fid *fhp));