usr/src/sys/nfs/nfsnode.h

/*
 * Copyright (c) 1989 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Rick Macklem at The University of Guelph.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 *      @(#)nfsnode.h   7.7 (Berkeley) %G%
 */

/*
 * The nfsnode is the nfs equivalent to ufs's inode. Any similarity
 * is purely coincidental.
 * There is a unique nfsnode allocated for each active file,
 * each current directory, each mounted-on file, text file, and the root.
 * An nfsnode is 'named' by its file handle. (nget/nfs_node.c)
 */

struct nfsnode {
        struct  nfsnode *n_chain[2];    /* must be first */
        nfsv2fh_t n_fh;                 /* NFS File Handle */
        long    n_flag;                 /* Flag for locking.. */
        struct  vnode *n_vnode; /* vnode associated with this nfsnode */
        long    n_attrstamp;    /* Time stamp (sec) for attributes */
        struct  vattr n_vattr;  /* Vnode attribute cache */
        struct  sillyrename *n_sillyrename;     /* Ptr to silly rename struct */
        u_long  n_size;         /* Current size of file */
        time_t  n_mtime;        /* Prev modify time to maintain data cache consistency*/
        int     n_error;        /* Save write error value */
        pid_t   n_lockholder;   /* holder of nfsnode lock */
        pid_t   n_lockwaiter;   /* most recent waiter for nfsnode lock */
};

#define n_forw          n_chain[0]
#define n_back          n_chain[1]

#ifdef KERNEL
/*
 * Convert between nfsnode pointers and vnode pointers
 */
#define VTONFS(vp)      ((struct nfsnode *)(vp)->v_data)
#define NFSTOV(np)      ((struct vnode *)(np)->n_vnode)
#endif
/*
 * Flags for n_flag
 */
#define NLOCKED         0x1     /* Lock the node for other local accesses */
#define NWANT           0x2     /* Want above lock */
#define NMODIFIED       0x4     /* Might have a modified buffer in bio */
#define NBUFFERED       0x8     /* Might have a buffer in bio */
#define NPAGEDON        0x10    /* Might have associated memory pages */
#define NWRITEERR       0x20    /* Flag write errors so close will know */