4.3BSD-UWisc/include/sys/vfs.h

/* NFSSRC @(#)vfs.h	2.1 86/04/11 */
/*	@(#)vfs.h 1.1 86/02/03 SMI	*/

/*
 * 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 singly linked list.
 */
struct vfs {
	struct vfs	*vfs_next;		/* next vfs in vfs list */
	struct vfsops	*vfs_op;		/* operations on vfs */
	struct vnode	*vfs_vnodecovered;	/* vnode we mounted on */
	int		vfs_flag;		/* flags */
	int		vfs_bsize;		/* native block size */
	u_short         vfs_exroot;             /* exported fs uid 0 mapping */
	short           vfs_exflags;            /* exported fs flags */
	caddr_t		vfs_data;		/* private data */
};

/*
 * vfs flags.
 * VFS_MLOCK lock the vfs so that name lookup cannot proceed past the vfs.
 * This keeps the subtree stable during mounts and unmounts.
 */
#define VFS_RDONLY	0x01		/* read only vfs */
#define VFS_MLOCK	0x02		/* lock vfs so that subtree is stable */
#define VFS_MWAIT	0x04		/* someone is waiting for lock */
#define VFS_NOSUID      0x08            /* someone is waiting for lock */
#define VFS_EXPORTED    0x10            /* file system is exported (NFS) */
/*
 * exported vfs flags.
 */
#define EX_RDONLY       0x01            /* exported read only */

/*
 * Operations supported on virtual file system.
 */
struct vfsops {
	int     (*vfs_mount)();
	int	(*vfs_unmount)();
	int	(*vfs_root)();
	int	(*vfs_statfs)();
	int	(*vfs_sync)();
};

#define VFS_MOUNT(VFSP, PATH, DATA) \
				(*(VFSP)->vfs_op->vfs_mount)(VFSP, PATH, DATA)
#define VFS_UNMOUNT(VFSP)		(*(VFSP)->vfs_op->vfs_unmount)(VFSP)
#define VFS_ROOT(VFSP, VPP)		(*(VFSP)->vfs_op->vfs_root)(VFSP,VPP)
#define VFS_STATFS(VFSP, SBP)		(*(VFSP)->vfs_op->vfs_statfs)(VFSP,SBP)
#define VFS_SYNC(VFSP)			(*(VFSP)->vfs_op->vfs_sync)(VFSP)

/*
 * file system statistics
 */
typedef long fsid_t[2];			/* file system id type */

struct statfs {
	long f_type;			/* type of info, zero for now */
	long f_bsize;			/* fundamental file system block size */
	long f_blocks;			/* total blocks in file system */
	long f_bfree;			/* free block 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 */
	long f_spare[7];		/* spare for later */
};

#ifdef KERNEL
/*
 * public operations
 */
extern void	vfs_mountroot();	/* mount the root */
extern int	vfs_add();		/* add a new vfs to mounted vfs list */
extern void	vfs_remove();		/* remove a vfs from mounted vfs list */
extern int	vfs_lock();		/* lock a vfs */
extern void	vfs_unlock();		/* unlock a vfs */

#define VFS_INIT(VFSP, OP, DATA)	{ \
	(VFSP)->vfs_next = (struct vfs *)0; \
	(VFSP)->vfs_op = (OP); \
	(VFSP)->vfs_flag = 0; \
	(VFSP)->vfs_exflags = 0; \
	(VFSP)->vfs_data = (DATA); \
}

/*
 * globals
 */
extern struct vfs *rootvfs;		/* ptr to root vfs structure */

#endif