vnode.h

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/*	$NetBSD: vnode.h,v 1.84 2000/11/27 08:39:52 chs Exp $	*/

/*
 * Copyright (c) 1989, 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.
 *
 *	@(#)vnode.h	8.17 (Berkeley) 5/20/95
 */

#ifndef _SYS_VNODE_H_
#define _SYS_VNODE_H_

#include <sys/lock.h>
#include <sys/queue.h>

/* XXX: clean up includes later */
#include <uvm/uvm_pglist.h>	/* XXX */
#include <uvm/uvm_object.h>	/* XXX */
#include <uvm/uvm_extern.h>	/* XXX */
#include <uvm/uvm_vnode.h>	/* XXX */

#ifdef OSKIT
#include <oskit/io/absio.h>
#include <oskit/io/blkio.h>
#endif

/*
 * The vnode is the focus of all file activity in UNIX.  There is a
 * unique vnode allocated for each active file, each current directory,
 * each mounted-on file, text file, and the root.
 */

/*
 * Vnode types.  VNON means no type.
 */
enum vtype	{ VNON, VREG, VDIR, VBLK, VCHR, VLNK, VSOCK, VFIFO, VBAD };

/*
 * Vnode tag types.
 * These are for the benefit of external programs only (e.g., pstat)
 * and should NEVER be inspected by the kernel.
 */
enum vtagtype	{
	VT_NON, VT_UFS, VT_NFS, VT_MFS, VT_MSDOSFS, VT_LFS, VT_LOFS, VT_FDESC,
	VT_PORTAL, VT_NULL, VT_UMAP, VT_KERNFS, VT_PROCFS, VT_AFS, VT_ISOFS,
	VT_UNION, VT_ADOSFS, VT_EXT2FS, VT_CODA, VT_FILECORE, VT_NTFS, VT_VFS,
	VT_OVERLAY
};

/*
 * Each underlying filesystem allocates its own private area and hangs
 * it from v_data.  If non-null, this area is freed in getnewvnode().
 */
LIST_HEAD(buflists, buf);

/*
 * Reading or writing any of these items requires holding the appropriate lock.
 * v_freelist is locked by the global vnode_free_list simple lock.
 * v_mntvnodes is locked by the global mntvnodes simple lock.
 * v_flag, v_usecount, v_holdcount and v_writecount are
 *     locked by the v_interlock simple lock
 */
struct vnode {
	struct uvm_vnode v_uvm;			/* uvm data */
#define v_flag v_uvm.u_flags
#define v_usecount v_uvm.u_obj.uo_refs
#define v_interlock v_uvm.u_obj.vmobjlock
#define v_numoutput v_uvm.u_nio
	long	v_writecount;			/* reference count of writers */
	long	v_holdcnt;			/* page & buffer references */
	daddr_t	v_lastr;			/* last read (read-ahead) */
	u_long	v_id;				/* capability identifier */
	struct	mount *v_mount;			/* ptr to vfs we are in */
	int 	(**v_op) __P((void *));		/* vnode operations vector */
	TAILQ_ENTRY(vnode) v_freelist;		/* vnode freelist */
	LIST_ENTRY(vnode) v_mntvnodes;		/* vnodes for mount point */
	struct	buflists v_cleanblkhd;		/* clean blocklist head */
	struct	buflists v_dirtyblkhd;		/* dirty blocklist head */
	LIST_ENTRY(vnode) v_synclist;		/* vnodes with dirty buffers */
	enum	vtype v_type;			/* vnode type */
	union {
		struct mount	*vu_mountedhere;/* ptr to mounted vfs (VDIR) */
		struct socket	*vu_socket;	/* unix ipc (VSOCK) */
		struct specinfo	*vu_specinfo;	/* device (VCHR, VBLK) */
		struct fifoinfo	*vu_fifoinfo;	/* fifo (VFIFO) */
	} v_un;
	struct	nqlease *v_lease;		/* Soft reference to lease */
	daddr_t	v_lastw;			/* last write (write cluster) */
	daddr_t	v_cstart;			/* start block of cluster */
	daddr_t	v_lasta;			/* last allocation */
	int	v_clen;				/* length of current cluster */
	int	v_ralen;			/* Read-ahead length */
	daddr_t	v_maxra;			/* last readahead block */
	struct	lock	v_lock;			/* lock for this vnode */
	struct	lock	v_glock;		/* getpage lock */
	struct	lock *v_vnlock;			/* pointer to vnode lock */
	enum	vtagtype v_tag;			/* type of underlying data */
	void 	*v_data;			/* private data for fs */
#ifdef OSKIT			/* XXX: should use v_data */
    	oskit_absio_t	*v_absio;
    	oskit_blkio_t	*v_blkio;
#endif
};
#define	v_mountedhere	v_un.vu_mountedhere
#define	v_socket	v_un.vu_socket
#define	v_specinfo	v_un.vu_specinfo
#define	v_fifoinfo	v_un.vu_fifoinfo
/*
 * All vnode locking operations should use vp->v_vnlock. For leaf filesystems
 * (such as ffs, lfs, msdosfs, etc), vp->v_vnlock = &vp->v_lock. For
 * stacked filesystems, vp->v_vnlock may equal lowervp->v_vnlock.
 *
 * vp->v_vnlock may also be NULL, which indicates that a leaf node does not
 * export a struct lock for vnode locking. Stacked filesystems (such as
 * nullfs) must call the underlying fs for locking. See layerfs_ routines
 * for examples.
 *
 * All filesystems must (pretend to) understand lockmanager flags.
 */

/*
 * Vnode flags.
 */
#define	VROOT		0x0001	/* root of its file system */
#define	VTEXT		0x0002	/* vnode is a pure text prototype */
	/* VSYSTEM only used to skip vflush()ing quota files */
#define	VSYSTEM		0x0004	/* vnode being used by kernel */
	/* VISTTY used when reading dead vnodes */
#define	VISTTY		0x0008	/* vnode represents a tty */
#define	VXLOCK		0x0100	/* vnode is locked to change underlying type */
#define	VXWANT		0x0200	/* process is waiting for vnode */
#define	VBWAIT		0x0400	/* waiting for output to complete */
#define	VALIASED	0x0800	/* vnode has an alias */
#define	VDIROP		0x1000	/* LFS: vnode is involved in a directory op */
#define VLAYER		0x2000	/* vnode is on a layer filesystem */
#define	VONWORKLST	0x4000	/* On syncer work-list */
#define VDIRTY		0x8000	/* vnode possibly has dirty pages */

#define VSIZENOTSET	((voff_t)-1)

/*
 * Vnode attributes.  A field value of VNOVAL represents a field whose value
 * is unavailable (getattr) or which is not to be changed (setattr).
 */
struct vattr {
	enum vtype	va_type;	/* vnode type (for create) */
	mode_t		va_mode;	/* files access mode and type */
	nlink_t		va_nlink;	/* number of references to file */
	uid_t		va_uid;		/* owner user id */
	gid_t		va_gid;		/* owner group id */
	long		va_fsid;	/* file system id (dev for now) */
	long		va_fileid;	/* file id */
	u_quad_t	va_size;	/* file size in bytes */
	long		va_blocksize;	/* blocksize preferred for i/o */
	struct timespec	va_atime;	/* time of last access */
	struct timespec	va_mtime;	/* time of last modification */
	struct timespec	va_ctime;	/* time file changed */
	u_long		va_gen;		/* generation number of file */
	u_long		va_flags;	/* flags defined for file */
	dev_t		va_rdev;	/* device the special file represents */
	u_quad_t	va_bytes;	/* bytes of disk space held by file */
	u_quad_t	va_filerev;	/* file modification number */
	u_int		va_vaflags;	/* operations flags, see below */
	long		va_spare;	/* remain quad aligned */
};

/*
 * Flags for va_vaflags.
 */
#define	VA_UTIMES_NULL	0x01		/* utimes argument was NULL */
#define VA_EXCLUSIVE	0x02		/* exclusive create request */

/*
 * Flags for ioflag.
 */
#define	IO_UNIT		0x01		/* do I/O as atomic unit */
#define	IO_APPEND	0x02		/* append write to end */
#define	IO_SYNC		(0x04|IO_DSYNC)	/* sync I/O file integrity completion */
#define	IO_NODELOCKED	0x08		/* underlying node already locked */
#define	IO_NDELAY	0x10		/* FNDELAY flag set in file table */
#define	IO_DSYNC	0x20		/* sync I/O data integrity completion */
#define	IO_ALTSEMANTICS	0x40		/* use alternate i/o semantics */

/*
 *  Modes.
 */
#define	VREAD	00004		/* read, write, execute permissions */
#define	VWRITE	00002
#define	VEXEC	00001

/*
 * Token indicating no attribute value yet assigned.
 */
#define	VNOVAL	(-1)

#ifdef _KERNEL
/*
 * Convert between vnode types and inode formats (since POSIX.1
 * defines mode word of stat structure in terms of inode formats).
 */
extern enum vtype	iftovt_tab[];
extern int		vttoif_tab[];
#define IFTOVT(mode)	(iftovt_tab[((mode) & S_IFMT) >> 12])
#define VTTOIF(indx)	(vttoif_tab[(int)(indx)])
#define MAKEIMODE(indx, mode)	(int)(VTTOIF(indx) | (mode))

/*
 * Flags to various vnode functions.
 */
#define	SKIPSYSTEM	0x0001		/* vflush: skip vnodes marked VSYSTEM */
#define	FORCECLOSE	0x0002		/* vflush: force file closeure */
#define	WRITECLOSE	0x0004		/* vflush: only close writeable files */
#define	DOCLOSE		0x0008		/* vclean: close active files */
#define	V_SAVE		0x0001		/* vinvalbuf: sync file first */

/*
 * Flags to various vnode operations.
 */
#define REVOKEALL	0x0001		/* revoke: revoke all aliases */

#define FSYNC_WAIT	0x0001		/* fsync: wait for completion */
#define FSYNC_DATAONLY	0x0002		/* fsync: hint: sync file data only */
#define FSYNC_RECLAIM	0x0004		/* fsync: hint: vnode is being reclaimed */
#define FSYNC_LAZY	0x0008		/* fsync: lazy sync (trickle) */

#define UPDATE_WAIT	0x0001		/* update: wait for completion */
#define UPDATE_DIROP	0x0002		/* update: hint to fs to wait or not */

#define	HOLDRELE(vp)	holdrele(vp)
#define	VHOLD(vp)	vhold(vp)
#define	VREF(vp)	vref(vp)
TAILQ_HEAD(freelst, vnode);
extern struct freelst vnode_hold_list;	/* free vnodes referencing buffers */
extern struct freelst vnode_free_list;	/* vnode free list */
extern struct simplelock vnode_free_list_slock;

#ifdef DIAGNOSTIC
#define	ilstatic
#else
#define	ilstatic static
#endif

ilstatic void holdrele __P((struct vnode *));
ilstatic void vhold __P((struct vnode *));
ilstatic void vref __P((struct vnode *));

#ifdef DIAGNOSTIC
#define	VATTR_NULL(vap)	vattr_null(vap)
#else
#define	VATTR_NULL(vap)	(*(vap) = va_null)	/* initialize a vattr */

/*
 * decrease buf or page ref
 */
static __inline void
holdrele(vp)