vnode.h

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/*
 * 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	8.7 (Berkeley) 2/4/94
 * $Id: vnode.h,v 1.80.2.1 1999/03/20 09:37:49 semenu Exp $
 */

#ifndef _SYS_VNODE_H_
#define	_SYS_VNODE_H_

#include <sys/queue.h>
#include <sys/select.h>
#include <sys/uio.h>

#include <machine/lock.h>

/*
 * 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_PC, VT_LFS, VT_LOFS, VT_FDESC,
	VT_PORTAL, VT_NULL, VT_UMAP, VT_KERNFS, VT_PROCFS, VT_AFS, VT_ISOFS,
	VT_UNION, VT_MSDOSFS, VT_DEVFS, VT_TFS, VT_VFS, VT_CODA, VT_NTFS
};

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

typedef	int 	vop_t __P((void *));
struct namecache;

/*
 * 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.
 * v_pollinfo is locked by the lock contained inside it.
 */
struct vnode {
	u_long	v_flag;				/* vnode flags (see below) */
	int	v_usecount;			/* reference count of users */
	int	v_writecount;			/* reference count of writers */
	int	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 */
	vop_t	**v_op;				/* 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 */
	long	v_numoutput;			/* num of writes in progress */
	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_maxio;			/* maximum I/O cluster size */
	struct vm_object *v_object;		/* Place to store VM object */
	struct	simplelock v_interlock;		/* lock on usecount and flag */
	struct	lock *v_vnlock;			/* used for non-locking fs's */
	enum	vtagtype v_tag;			/* type of underlying data */
	void 	*v_data;			/* private data for fs */
	LIST_HEAD(, namecache) v_cache_src;	/* Cache entries from us */
	TAILQ_HEAD(, namecache) v_cache_dst;	/* Cache entries to us */
	struct	vnode *v_dd;			/* .. vnode */
	u_long	v_ddid;				/* .. capability identifier */
	struct	{
		struct	simplelock vpi_lock;	/* lock to protect below */
		struct	selinfo vpi_selinfo;	/* identity of poller(s) */
		short	vpi_events;		/* what they are looking for */
		short	vpi_revents;		/* what has happened */
	} v_pollinfo;
#ifdef	DEBUG_LOCKS
	const char *filename;			/* Source file doing locking */
	int line;				/* Line number doing locking */
#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

#define	VN_POLLEVENT(vp, events)				\
	do {							\
		if ((vp)->v_pollinfo.vpi_events & (events))	\
			vn_pollevent((vp), (events));		\
	} while (0)

/*
 * Vnode flags.
 */
#define	VROOT		0x00001	/* root of its file system */
#define	VTEXT		0x00002	/* vnode is a pure text prototype */
#define	VSYSTEM		0x00004	/* vnode being used by kernel */
#define	VISTTY		0x00008	/* vnode represents a tty */
#define	VXLOCK		0x00100	/* vnode is locked to change underlying type */
#define	VXWANT		0x00200	/* process is waiting for vnode */
#define	VBWAIT		0x00400	/* waiting for output to complete */
#define	VALIASED	0x00800	/* vnode has an alias */
#define	VDIROP		0x01000	/* LFS: vnode is involved in a directory op */
#define	VOBJBUF		0x02000	/* Allocate buffers in VM object */
#define	VNINACT		0x04000	/* LFS: skip ufs_inactive() in lfs_vunref */
#define	VAGE		0x08000	/* Insert vnode at head of free list */
#define	VOLOCK		0x10000	/* vnode is locked waiting for an object */
#define	VOWANT		0x20000	/* a process is waiting for VOLOCK */
#define	VDOOMED		0x40000	/* This vnode is being recycled */
#define	VFREE		0x80000	/* This vnode is on the freelist */
#define	VTBFREE		0x100000 /* This vnode is on the to-be-freelist */
#define	VONWORKLST	0x200000 /* On syncer work-list */
#define	VMOUNT		0x400000 /* Mount in progress */

/*
 * 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) */
	u_short		va_mode;	/* files access mode and type */
	short		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		/* do I/O synchronously */
#define	IO_NODELOCKED	0x08		/* underlying node already locked */
#define	IO_NDELAY	0x10		/* FNDELAY flag set in file table */
#define	IO_VMIO		0x20		/* data already in VMIO space */
#define	IO_INVAL	0x40		/* invalidate after I/O */

/*
 *  Modes.  Some values same as Ixxx entries from inode.h for now.
 */
#define	VSUID	04000		/* set user id on execution */
#define	VSGID	02000		/* set group id on execution */
#define	VSVTX	01000		/* save swapped text even after use */
#define	VREAD	00400		/* read, write, execute permissions */
#define	VWRITE	00200
#define	VEXEC	00100

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

#ifdef KERNEL

#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_VNODE);
#endif

/*
 * 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 closure */
#define	WRITECLOSE	0x0004		/* vflush: only close writable files */
#define	DOCLOSE		0x0008		/* vclean: close active files */
#define	V_SAVE		0x0001		/* vinvalbuf: sync file first */
#define	REVOKEALL	0x0001		/* vop_revoke: revoke all aliases */

#define	VREF(vp)	vref(vp)


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

#define	NULLVP	((struct vnode *)NULL)

#if defined(VFS_LKM) && !defined(KLD_MODULE)
#define	VNODEOP_SET(f) DATA_SET(MODVNOPS,f)
#else
#define	VNODEOP_SET(f) \
	SYSINIT(f##init, SI_SUB_VFS, SI_ORDER_SECOND, vfs_add_vnodeops, &f); \
	SYSUNINIT(f##uninit, SI_SUB_VFS, SI_ORDER_SECOND, vfs_rm_vnodeops, &f);
#endif

/*
 * Global vnode data.
 */
extern	struct vnode *rootvnode;	/* root (i.e. "/") vnode */
extern	int desiredvnodes;		/* number of vnodes desired */
extern	time_t syncdelay;		/* time to delay syncing vnodes */
extern	int rushjob;		/* # of slots filesys_syncer should run ASAP */
extern	struct vm_zone *namei_zone;
extern	int prtactive;			/* nonzero to call vprint() */
extern	struct vattr va_null;		/* predefined null vattr structure */
extern	int vfs_ioopt;

/*
 * Macro/function to check for client cache inconsistency w.r.t. leasing.