kernel - Improve physio performance

[dragonfly.git] / sys / vfs / nfs / nfs_subs.c

/*
 * Copyright (c) 1989, 1993
 *      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, 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. 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.
 *
 *      @(#)nfs_subs.c  8.8 (Berkeley) 5/22/95
 * $FreeBSD: /repoman/r/ncvs/src/sys/nfsclient/nfs_subs.c,v 1.128 2004/04/14 23:23:55 peadar Exp $
 */

/*
 * These functions support the macros and help fiddle mbuf chains for
 * the nfs op functions. They do things like create the rpc header and
 * copy data between mbuf chains and uio lists.
 */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/nlookup.h>
#include <sys/namei.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/malloc.h>
#include <sys/sysent.h>
#include <sys/syscall.h>
#include <sys/conf.h>
#include <sys/objcache.h>

#include <vm/vm.h>
#include <vm/vm_object.h>
#include <vm/vm_extern.h>

#include <sys/buf2.h>

#include "rpcv2.h"
#include "nfsproto.h"
#include "nfs.h"
#include "nfsmount.h"
#include "nfsnode.h"
#include "xdr_subs.h"
#include "nfsm_subs.h"
#include "nfsrtt.h"

#include <netinet/in.h>

MALLOC_DEFINE(M_NFSMOUNT, "NFS mount", "NFS mount");

/*
 * Data items converted to xdr at startup, since they are constant
 * This is kinda hokey, but may save a little time doing byte swaps
 */
u_int32_t nfs_xdrneg1;
u_int32_t rpc_reply, rpc_msgdenied, rpc_mismatch, rpc_vers;
u_int32_t rpc_auth_unix, rpc_msgaccepted, rpc_call, rpc_autherr;
u_int32_t rpc_auth_kerb;
u_int32_t nfs_prog, nfs_true, nfs_false;

/* And other global data */
static enum vtype nv2tov_type[8]= {
        VNON, VREG, VDIR, VBLK, VCHR, VLNK, VNON,  VNON 
};
enum vtype nv3tov_type[8]= {
        VNON, VREG, VDIR, VBLK, VCHR, VLNK, VSOCK, VFIFO
};

int nfs_ticks;

/*
 * Protect master lists only.  Primary protection uses the per-mount
 * and per nfssvc_sock tokens.
 */
struct lwkt_token nfs_token = LWKT_TOKEN_INITIALIZER(unp_token);

static long nfs_pbuf_freecnt = -1;      /* start out unlimited */

struct nfsmount_head nfs_mountq = TAILQ_HEAD_INITIALIZER(nfs_mountq);
struct nfssvc_sockhead nfssvc_sockhead;
int nfssvc_sockhead_flag;
struct nfsd_head nfsd_head;
int nfsd_head_flag;
struct nfs_bufq nfs_bufq;
struct nqfhhashhead *nqfhhashtbl;
u_long nqfhhash;

static int nfs_prev_nfssvc_sy_narg;
static sy_call_t *nfs_prev_nfssvc_sy_call;

#ifndef NFS_NOSERVER

/*
 * Mapping of old NFS Version 2 RPC numbers to generic numbers.
 */
int nfsv3_procid[NFS_NPROCS] = {
        NFSPROC_NULL,
        NFSPROC_GETATTR,
        NFSPROC_SETATTR,
        NFSPROC_NOOP,
        NFSPROC_LOOKUP,
        NFSPROC_READLINK,
        NFSPROC_READ,
        NFSPROC_NOOP,
        NFSPROC_WRITE,
        NFSPROC_CREATE,
        NFSPROC_REMOVE,
        NFSPROC_RENAME,
        NFSPROC_LINK,
        NFSPROC_SYMLINK,
        NFSPROC_MKDIR,
        NFSPROC_RMDIR,
        NFSPROC_READDIR,
        NFSPROC_FSSTAT,
        NFSPROC_NOOP,
        NFSPROC_NOOP,
        NFSPROC_NOOP,
        NFSPROC_NOOP,
        NFSPROC_NOOP,
        NFSPROC_NOOP,
        NFSPROC_NOOP,
        NFSPROC_NOOP
};

#endif /* NFS_NOSERVER */
/*
 * and the reverse mapping from generic to Version 2 procedure numbers
 */
int nfsv2_procid[NFS_NPROCS] = {
        NFSV2PROC_NULL,
        NFSV2PROC_GETATTR,
        NFSV2PROC_SETATTR,
        NFSV2PROC_LOOKUP,
        NFSV2PROC_NOOP,
        NFSV2PROC_READLINK,
        NFSV2PROC_READ,
        NFSV2PROC_WRITE,
        NFSV2PROC_CREATE,
        NFSV2PROC_MKDIR,
        NFSV2PROC_SYMLINK,
        NFSV2PROC_CREATE,
        NFSV2PROC_REMOVE,
        NFSV2PROC_RMDIR,
        NFSV2PROC_RENAME,
        NFSV2PROC_LINK,
        NFSV2PROC_READDIR,
        NFSV2PROC_NOOP,
        NFSV2PROC_STATFS,
        NFSV2PROC_NOOP,
        NFSV2PROC_NOOP,
        NFSV2PROC_NOOP,
        NFSV2PROC_NOOP,
        NFSV2PROC_NOOP,
        NFSV2PROC_NOOP,
        NFSV2PROC_NOOP,
};

#ifndef NFS_NOSERVER
/*
 * Maps errno values to nfs error numbers.
 * Use NFSERR_IO as the catch all for ones not specifically defined in
 * RFC 1094.
 */
static u_char nfsrv_v2errmap[ELAST] = {
  NFSERR_PERM,  NFSERR_NOENT,   NFSERR_IO,      NFSERR_IO,      NFSERR_IO,
  NFSERR_NXIO,  NFSERR_IO,      NFSERR_IO,      NFSERR_IO,      NFSERR_IO,
  NFSERR_IO,    NFSERR_IO,      NFSERR_ACCES,   NFSERR_IO,      NFSERR_IO,
  NFSERR_IO,    NFSERR_EXIST,   NFSERR_IO,      NFSERR_NODEV,   NFSERR_NOTDIR,
  NFSERR_ISDIR, NFSERR_IO,      NFSERR_IO,      NFSERR_IO,      NFSERR_IO,
  NFSERR_IO,    NFSERR_FBIG,    NFSERR_NOSPC,   NFSERR_IO,      NFSERR_ROFS,
  NFSERR_IO,    NFSERR_IO,      NFSERR_IO,      NFSERR_IO,      NFSERR_IO,
  NFSERR_IO,    NFSERR_IO,      NFSERR_IO,      NFSERR_IO,      NFSERR_IO,
  NFSERR_IO,    NFSERR_IO,      NFSERR_IO,      NFSERR_IO,      NFSERR_IO,
  NFSERR_IO,    NFSERR_IO,      NFSERR_IO,      NFSERR_IO,      NFSERR_IO,
  NFSERR_IO,    NFSERR_IO,      NFSERR_IO,      NFSERR_IO,      NFSERR_IO,
  NFSERR_IO,    NFSERR_IO,      NFSERR_IO,      NFSERR_IO,      NFSERR_IO,
  NFSERR_IO,    NFSERR_IO,      NFSERR_NAMETOL, NFSERR_IO,      NFSERR_IO,
  NFSERR_NOTEMPTY, NFSERR_IO,   NFSERR_IO,      NFSERR_DQUOT,   NFSERR_STALE,
  NFSERR_IO,    NFSERR_IO,      NFSERR_IO,      NFSERR_IO,      NFSERR_IO,
  NFSERR_IO,    NFSERR_IO,      NFSERR_IO,      NFSERR_IO,      NFSERR_IO,
  NFSERR_IO,    NFSERR_IO,      NFSERR_IO,      NFSERR_IO,      NFSERR_IO,
  NFSERR_IO /* << Last is 86 */
};

/*
 * Maps errno values to nfs error numbers.
 * Although it is not obvious whether or not NFS clients really care if
 * a returned error value is in the specified list for the procedure, the
 * safest thing to do is filter them appropriately. For Version 2, the
 * X/Open XNFS document is the only specification that defines error values
 * for each RPC (The RFC simply lists all possible error values for all RPCs),
 * so I have decided to not do this for Version 2.
 * The first entry is the default error return and the rest are the valid
 * errors for that RPC in increasing numeric order.
 */
static short nfsv3err_null[] = {
        0,
        0,
};

static short nfsv3err_getattr[] = {
        NFSERR_IO,
        NFSERR_IO,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_SERVERFAULT,
        0,
};

static short nfsv3err_setattr[] = {
        NFSERR_IO,
        NFSERR_PERM,
        NFSERR_IO,
        NFSERR_ACCES,
        NFSERR_INVAL,
        NFSERR_NOSPC,
        NFSERR_ROFS,
        NFSERR_DQUOT,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_NOT_SYNC,
        NFSERR_SERVERFAULT,
        0,
};

static short nfsv3err_lookup[] = {
        NFSERR_IO,
        NFSERR_NOENT,
        NFSERR_IO,
        NFSERR_ACCES,
        NFSERR_NOTDIR,
        NFSERR_NAMETOL,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_SERVERFAULT,
        0,
};

static short nfsv3err_access[] = {
        NFSERR_IO,
        NFSERR_IO,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_SERVERFAULT,
        0,
};

static short nfsv3err_readlink[] = {
        NFSERR_IO,
        NFSERR_IO,
        NFSERR_ACCES,
        NFSERR_INVAL,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_NOTSUPP,
        NFSERR_SERVERFAULT,
        0,
};

static short nfsv3err_read[] = {
        NFSERR_IO,
        NFSERR_IO,
        NFSERR_NXIO,
        NFSERR_ACCES,
        NFSERR_INVAL,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_SERVERFAULT,
        0,
};

static short nfsv3err_write[] = {
        NFSERR_IO,
        NFSERR_IO,
        NFSERR_ACCES,
        NFSERR_INVAL,
        NFSERR_FBIG,
        NFSERR_NOSPC,
        NFSERR_ROFS,
        NFSERR_DQUOT,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_SERVERFAULT,
        0,
};

static short nfsv3err_create[] = {
        NFSERR_IO,
        NFSERR_IO,
        NFSERR_ACCES,
        NFSERR_EXIST,
        NFSERR_NOTDIR,
        NFSERR_NOSPC,
        NFSERR_ROFS,
        NFSERR_NAMETOL,
        NFSERR_DQUOT,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_NOTSUPP,
        NFSERR_SERVERFAULT,
        0,
};

static short nfsv3err_mkdir[] = {
        NFSERR_IO,
        NFSERR_IO,
        NFSERR_ACCES,
        NFSERR_EXIST,
        NFSERR_NOTDIR,
        NFSERR_NOSPC,
        NFSERR_ROFS,
        NFSERR_NAMETOL,
        NFSERR_DQUOT,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_NOTSUPP,
        NFSERR_SERVERFAULT,
        0,
};

static short nfsv3err_symlink[] = {
        NFSERR_IO,
        NFSERR_IO,
        NFSERR_ACCES,
        NFSERR_EXIST,
        NFSERR_NOTDIR,
        NFSERR_NOSPC,
        NFSERR_ROFS,
        NFSERR_NAMETOL,
        NFSERR_DQUOT,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_NOTSUPP,
        NFSERR_SERVERFAULT,
        0,
};

static short nfsv3err_mknod[] = {
        NFSERR_IO,
        NFSERR_IO,
        NFSERR_ACCES,
        NFSERR_EXIST,
        NFSERR_NOTDIR,
        NFSERR_NOSPC,
        NFSERR_ROFS,
        NFSERR_NAMETOL,
        NFSERR_DQUOT,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_NOTSUPP,
        NFSERR_SERVERFAULT,
        NFSERR_BADTYPE,
        0,
};

static short nfsv3err_remove[] = {
        NFSERR_IO,
        NFSERR_NOENT,
        NFSERR_IO,
        NFSERR_ACCES,
        NFSERR_NOTDIR,
        NFSERR_ROFS,
        NFSERR_NAMETOL,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_SERVERFAULT,
        0,
};

static short nfsv3err_rmdir[] = {
        NFSERR_IO,
        NFSERR_NOENT,
        NFSERR_IO,
        NFSERR_ACCES,
        NFSERR_EXIST,
        NFSERR_NOTDIR,
        NFSERR_INVAL,
        NFSERR_ROFS,
        NFSERR_NAMETOL,
        NFSERR_NOTEMPTY,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_NOTSUPP,
        NFSERR_SERVERFAULT,
        0,
};

static short nfsv3err_rename[] = {
        NFSERR_IO,
        NFSERR_NOENT,
        NFSERR_IO,
        NFSERR_ACCES,
        NFSERR_EXIST,
        NFSERR_XDEV,
        NFSERR_NOTDIR,
        NFSERR_ISDIR,
        NFSERR_INVAL,
        NFSERR_NOSPC,
        NFSERR_ROFS,
        NFSERR_MLINK,
        NFSERR_NAMETOL,
        NFSERR_NOTEMPTY,
        NFSERR_DQUOT,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_NOTSUPP,
        NFSERR_SERVERFAULT,
        0,
};

static short nfsv3err_link[] = {
        NFSERR_IO,
        NFSERR_IO,
        NFSERR_ACCES,
        NFSERR_EXIST,
        NFSERR_XDEV,
        NFSERR_NOTDIR,
        NFSERR_INVAL,
        NFSERR_NOSPC,
        NFSERR_ROFS,
        NFSERR_MLINK,
        NFSERR_NAMETOL,
        NFSERR_DQUOT,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_NOTSUPP,
        NFSERR_SERVERFAULT,
        0,
};

static short nfsv3err_readdir[] = {
        NFSERR_IO,
        NFSERR_IO,
        NFSERR_ACCES,
        NFSERR_NOTDIR,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_BAD_COOKIE,
        NFSERR_TOOSMALL,
        NFSERR_SERVERFAULT,
        0,
};

static short nfsv3err_readdirplus[] = {
        NFSERR_IO,
        NFSERR_IO,
        NFSERR_ACCES,
        NFSERR_NOTDIR,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_BAD_COOKIE,
        NFSERR_NOTSUPP,
        NFSERR_TOOSMALL,
        NFSERR_SERVERFAULT,
        0,
};

static short nfsv3err_fsstat[] = {
        NFSERR_IO,
        NFSERR_IO,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_SERVERFAULT,
        0,
};

static short nfsv3err_fsinfo[] = {
        NFSERR_STALE,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_SERVERFAULT,
        0,
};

static short nfsv3err_pathconf[] = {
        NFSERR_STALE,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_SERVERFAULT,
        0,
};

static short nfsv3err_commit[] = {
        NFSERR_IO,
        NFSERR_IO,
        NFSERR_STALE,
        NFSERR_BADHANDLE,
        NFSERR_SERVERFAULT,
        0,
};

static short *nfsrv_v3errmap[] = {
        nfsv3err_null,
        nfsv3err_getattr,
        nfsv3err_setattr,
        nfsv3err_lookup,
        nfsv3err_access,
        nfsv3err_readlink,
        nfsv3err_read,
        nfsv3err_write,
        nfsv3err_create,
        nfsv3err_mkdir,
        nfsv3err_symlink,
        nfsv3err_mknod,
        nfsv3err_remove,
        nfsv3err_rmdir,
        nfsv3err_rename,
        nfsv3err_link,
        nfsv3err_readdir,
        nfsv3err_readdirplus,
        nfsv3err_fsstat,
        nfsv3err_fsinfo,
        nfsv3err_pathconf,
        nfsv3err_commit,
};

#endif /* NFS_NOSERVER */

struct nfssvc_args;
extern int sys_nfssvc(struct proc *, struct nfssvc_args *, int *);

/*
 * This needs to return a monotonically increasing or close to monotonically
 * increasing result, otherwise the write gathering queues won't work 
 * properly.
 */
u_quad_t
nfs_curusec(void) 
{
        struct timeval tv;
        
        getmicrouptime(&tv);
        return ((u_quad_t)tv.tv_sec * 1000000 + (u_quad_t)tv.tv_usec);
}

/*
 * Called once to initialize data structures...
 */
int
nfs_init(struct vfsconf *vfsp)
{
        callout_init(&nfs_timer_handle);
        nfsmount_objcache = objcache_create_simple(M_NFSMOUNT, sizeof(struct nfsmount));

        nfs_mount_type = vfsp->vfc_typenum;
        nfsrtt.pos = 0;
        rpc_vers = txdr_unsigned(RPC_VER2);
        rpc_call = txdr_unsigned(RPC_CALL);
        rpc_reply = txdr_unsigned(RPC_REPLY);
        rpc_msgdenied = txdr_unsigned(RPC_MSGDENIED);
        rpc_msgaccepted = txdr_unsigned(RPC_MSGACCEPTED);
        rpc_mismatch = txdr_unsigned(RPC_MISMATCH);
        rpc_autherr = txdr_unsigned(RPC_AUTHERR);
        rpc_auth_unix = txdr_unsigned(RPCAUTH_UNIX);
        rpc_auth_kerb = txdr_unsigned(RPCAUTH_KERB4);
        nfs_prog = txdr_unsigned(NFS_PROG);
        nfs_true = txdr_unsigned(TRUE);
        nfs_false = txdr_unsigned(FALSE);
        nfs_xdrneg1 = txdr_unsigned(-1);
        nfs_ticks = (hz * NFS_TICKINTVL + 500) / 1000;
        if (nfs_ticks < 1)
                nfs_ticks = 1;
        nfs_nhinit();                   /* Init the nfsnode table */
#ifndef NFS_NOSERVER
        nfsrv_init(0);                  /* Init server data structures */
        nfsrv_initcache();              /* Init the server request cache */
#endif

        /*
         * Mainly for vkernel operation.  If memory is severely limited
         */
        if (nfs_maxasyncbio > nmbclusters * MCLBYTES / NFS_MAXDATA / 3)
                nfs_maxasyncbio = nmbclusters * MCLBYTES / NFS_MAXDATA / 3;
        if (nfs_maxasyncbio < 4)
                nfs_maxasyncbio = 4;

        /*
         * Initialize reply list and start timer
         */
        nfs_timer_callout(0);

        nfs_prev_nfssvc_sy_narg = sysent[SYS_nfssvc].sy_narg;
        sysent[SYS_nfssvc].sy_narg = 2;
        nfs_prev_nfssvc_sy_call = sysent[SYS_nfssvc].sy_call;
        sysent[SYS_nfssvc].sy_call = (sy_call_t *)sys_nfssvc;

        nfs_pbuf_freecnt = nswbuf_kva / 2 + 1;

        return (0);
}

int
nfs_uninit(struct vfsconf *vfsp)
{
        callout_stop(&nfs_timer_handle);
        nfs_mount_type = -1;
        sysent[SYS_nfssvc].sy_narg = nfs_prev_nfssvc_sy_narg;
        sysent[SYS_nfssvc].sy_call = nfs_prev_nfssvc_sy_call;
        return (0);
}

/*
 * Attribute cache routines.
 * nfs_loadattrcache() - loads or updates the cache contents from attributes
 *      that are on the mbuf list
 * nfs_getattrcache() - returns valid attributes if found in cache, returns
 *      error otherwise
 */

/*
 * Load the attribute cache (that lives in the nfsnode entry) with
 * the values on the mbuf list.  Load *vaper with the attributes.  vaper
 * may be NULL.
 *
 * As a side effect n_mtime, which we use to determine if the file was
 * modified by some other host, is set to the attribute timestamp and
 * NRMODIFIED is set if the two values differ.
 *
 * WARNING: the mtime loaded into vaper does not necessarily represent
 * n_mtime or n_attr.mtime due to NACC and NUPD.
 */
int
nfs_loadattrcache(struct vnode *vp, struct mbuf **mdp, caddr_t *dposp,
                  struct vattr *vaper, int lattr_flags)
{
        struct vattr *vap;
        struct nfs_fattr *fp;
        struct nfsnode *np;
        int32_t t1;
        caddr_t cp2;
        int error = 0;
        int rmajor, rminor;
        udev_t rdev;
        struct mbuf *md;
        enum vtype vtyp;
        u_short vmode;
        struct timespec mtime;
        int v3 = NFS_ISV3(vp);

        md = *mdp;
        t1 = (mtod(md, caddr_t) + md->m_len) - *dposp;
        if ((error = nfsm_disct(mdp, dposp, NFSX_FATTR(v3), t1, &cp2)) != 0)
                return (error);
        fp = (struct nfs_fattr *)cp2;
        if (v3) {
                vtyp = nfsv3tov_type(fp->fa_type);
                vmode = fxdr_unsigned(u_short, fp->fa_mode);
                rmajor = (int)fxdr_unsigned(int, fp->fa3_rdev.specdata1);
                rminor = (int)fxdr_unsigned(int, fp->fa3_rdev.specdata2);
                fxdr_nfsv3time(&fp->fa3_mtime, &mtime);
        } else {
                vtyp = nfsv2tov_type(fp->fa_type);
                vmode = fxdr_unsigned(u_short, fp->fa_mode);
                /*
                 * XXX
                 *
                 * The duplicate information returned in fa_type and fa_mode
                 * is an ambiguity in the NFS version 2 protocol.
                 *
                 * VREG should be taken literally as a regular file.  If a
                 * server intents to return some type information differently
                 * in the upper bits of the mode field (e.g. for sockets, or
                 * FIFOs), NFSv2 mandates fa_type to be VNON.  Anyway, we
                 * leave the examination of the mode bits even in the VREG
                 * case to avoid breakage for bogus servers, but we make sure
                 * that there are actually type bits set in the upper part of
                 * fa_mode (and failing that, trust the va_type field).
                 *
                 * NFSv3 cleared the issue, and requires fa_mode to not
                 * contain any type information (while also introduing sockets
                 * and FIFOs for fa_type).
                 */
                if (vtyp == VNON || (vtyp == VREG && (vmode & S_IFMT) != 0))
                        vtyp = IFTOVT(vmode);
                rdev = fxdr_unsigned(int32_t, fp->fa2_rdev);
                rmajor = umajor(rdev);
                rminor = uminor(rdev);
                fxdr_nfsv2time(&fp->fa2_mtime, &mtime);

                /*
                 * Really ugly NFSv2 kludge.
                 */
                if (vtyp == VCHR && rdev == (udev_t)0xffffffff)
                        vtyp = VFIFO;
        }

        /*
         * If v_type == VNON it is a new node, so fill in the v_type,
         * n_mtime fields. Check to see if it represents a special
         * device, and if so, check for a possible alias. Once the
         * correct vnode has been obtained, fill in the rest of the
         * information.
         */
        np = VTONFS(vp);
        if (vp->v_type != vtyp) {
                nfs_setvtype(vp, vtyp);
                if (vp->v_type == VFIFO) {
                        vp->v_ops = &vp->v_mount->mnt_vn_fifo_ops;
                } else if (vp->v_type == VCHR || vp->v_type == VBLK) {
                        vp->v_ops = &vp->v_mount->mnt_vn_spec_ops;
                        addaliasu(vp, rmajor, rminor);
                } else {
                        vp->v_ops = &vp->v_mount->mnt_vn_use_ops;
                }
                np->n_mtime = mtime.tv_sec;
        } else if (np->n_mtime != mtime.tv_sec) {
                /*
                 * If we haven't modified the file locally and the server
                 * timestamp does not match, then the server probably
                 * modified the file.  We must flag this condition so
                 * the proper syncnronization can be done.  We do not
                 * try to synchronize the state here because that
                 * could lead to an endless recursion.
                 *
                 * XXX loadattrcache can be set during the reply to a write,
                 * before the write timestamp is properly processed.  To
                 * avoid unconditionally setting the rmodified bit (which
                 * has the effect of flushing the cache), we only do this
                 * check if the lmodified bit is not set.
                 */
                np->n_mtime = mtime.tv_sec;
                if ((lattr_flags & NFS_LATTR_NOMTIMECHECK) == 0)
                        np->n_flag |= NRMODIFIED;
        }
        vap = &np->n_vattr;
        vap->va_type = vtyp;
        vap->va_mode = (vmode & 07777);
        vap->va_rmajor = rmajor;
        vap->va_rminor = rminor;
        vap->va_mtime = mtime;
        vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
        if (v3) {
                vap->va_nlink = fxdr_unsigned(u_short, fp->fa_nlink);
                vap->va_uid = fxdr_unsigned(uid_t, fp->fa_uid);
                vap->va_gid = fxdr_unsigned(gid_t, fp->fa_gid);
                vap->va_size = fxdr_hyper(&fp->fa3_size);
                vap->va_blocksize = NFS_FABLKSIZE;
                vap->va_bytes = fxdr_hyper(&fp->fa3_used);
                vap->va_fileid = fxdr_hyper(&fp->fa3_fileid);
                fxdr_nfsv3time(&fp->fa3_atime, &vap->va_atime);
                fxdr_nfsv3time(&fp->fa3_ctime, &vap->va_ctime);
                vap->va_flags = 0;
                vap->va_filerev = 0;
        } else {
                vap->va_nlink = fxdr_unsigned(u_short, fp->fa_nlink);
                vap->va_uid = fxdr_unsigned(uid_t, fp->fa_uid);
                vap->va_gid = fxdr_unsigned(gid_t, fp->fa_gid);
                vap->va_size = fxdr_unsigned(u_int32_t, fp->fa2_size);
                vap->va_blocksize = fxdr_unsigned(int32_t, fp->fa2_blocksize);
                vap->va_bytes = (u_quad_t)fxdr_unsigned(int32_t, fp->fa2_blocks)
                    * NFS_FABLKSIZE;
                vap->va_fileid = fxdr_unsigned(int32_t, fp->fa2_fileid);
                fxdr_nfsv2time(&fp->fa2_atime, &vap->va_atime);
                vap->va_flags = 0;
                vap->va_ctime.tv_sec = fxdr_unsigned(u_int32_t,
                    fp->fa2_ctime.nfsv2_sec);
                vap->va_ctime.tv_nsec = 0;
                vap->va_gen = fxdr_unsigned(u_int32_t,fp->fa2_ctime.nfsv2_usec);
                vap->va_filerev = 0;
        }
        np->n_attrstamp = time_uptime;
        if (vap->va_size != np->n_size) {
                if (vap->va_type == VREG) {
                        /*
                         * Get rid of all the junk we had before and just
                         * set NRMODIFIED if NLMODIFIED is 0.  Depend on
                         * occassionally flushing our dirty buffers to
                         * clear both the NLMODIFIED and NRMODIFIED flags.
                         */
                        if ((np->n_flag & NLMODIFIED) == 0)
                                np->n_flag |= NRMODIFIED;
#if 0
                        if ((lattr_flags & NFS_LATTR_NOSHRINK) && 
                            vap->va_size < np->n_size) {
                                /*
                                 * We've been told not to shrink the file;
                                 * zero np->n_attrstamp to indicate that
                                 * the attributes are stale.
                                 *
                                 * This occurs primarily due to recursive
                                 * NFS ops that are executed during periods
                                 * where we cannot safely reduce the size of
                                 * the file.
                                 *
                                 * Additionally, write rpcs are broken down
                                 * into buffers and np->n_size is 
                                 * pre-extended.  Setting NRMODIFIED here
                                 * can result in n_size getting reset to a
                                 * lower value, which is NOT what we want.
                                 * XXX this needs to be cleaned up a lot 
                                 * more.
                                 */
                                vap->va_size = np->n_size;
                                np->n_attrstamp = 0;
                                if ((np->n_flag & NLMODIFIED) == 0)
                                        np->n_flag |= NRMODIFIED;
                        } else if (np->n_flag & NLMODIFIED) {
                                /*
                                 * We've modified the file: Use the larger
                                 * of our size, and the server's size.  At
                                 * this point the cache coherency is all
                                 * shot to hell.  To try to handle multiple
                                 * clients appending to the file at the same
                                 * time mark that the server has changed
                                 * the file if the server's notion of the
                                 * file size is larger then our notion.
                                 *
                                 * XXX this needs work.
                                 */
                                if (vap->va_size < np->n_size) {
                                        vap->va_size = np->n_size;
                                } else {
                                        np->n_size = vap->va_size;
                                        np->n_flag |= NRMODIFIED;
                                }
                        } else {
                                /*
                                 * Someone changed the file's size on the
                                 * server and there are no local changes
                                 * to get in the way, set the size and mark
                                 * it.
                                 */
                                np->n_size = vap->va_size;
                                np->n_flag |= NRMODIFIED;
                        }
                        nvnode_pager_setsize(vp, np->n_size, XXX);
#endif
                } else {
                        np->n_size = vap->va_size;
                }
        }
        if (vaper != NULL) {
                bcopy((caddr_t)vap, (caddr_t)vaper, sizeof(*vap));
                if (np->n_flag & NCHG) {
                        if (np->n_flag & NACC)
                                vaper->va_atime = np->n_atim;
                        if (np->n_flag & NUPD)
                                vaper->va_mtime = np->n_mtim;
                }
        }
        return (0);
}

#ifdef NFS_ACDEBUG
#include <sys/sysctl.h>
SYSCTL_DECL(_vfs_nfs);
static int nfs_acdebug;
SYSCTL_INT(_vfs_nfs, OID_AUTO, acdebug, CTLFLAG_RW, &nfs_acdebug, 0, "");
#endif

/*
 * Check the time stamp
 * If the cache is valid, copy contents to *vap and return 0
 * otherwise return an error
 */
int
nfs_getattrcache(struct vnode *vp, struct vattr *vaper)
{
        struct nfsnode *np;
        struct vattr *vap;
        struct nfsmount *nmp;
        int timeo;

        np = VTONFS(vp);
        vap = &np->n_vattr;
        nmp = VFSTONFS(vp->v_mount);

        /*
         * Dynamic timeout based on how recently the file was modified.
         * n_mtime is always valid.
         */
        timeo = (get_approximate_time_t() - np->n_mtime) / 60;

#ifdef NFS_ACDEBUG
        if (nfs_acdebug>1)
                kprintf("nfs_getattrcache: initial timeo = %d\n", timeo);
#endif

        if (vap->va_type == VDIR) {
                if ((np->n_flag & NLMODIFIED) || timeo < nmp->nm_acdirmin)
                        timeo = nmp->nm_acdirmin;
                else if (timeo > nmp->nm_acdirmax)
                        timeo = nmp->nm_acdirmax;
        } else {
                if ((np->n_flag & NLMODIFIED) || timeo < nmp->nm_acregmin)
                        timeo = nmp->nm_acregmin;
                else if (timeo > nmp->nm_acregmax)
                        timeo = nmp->nm_acregmax;
        }

#ifdef NFS_ACDEBUG
        if (nfs_acdebug > 2)
                kprintf("acregmin %d; acregmax %d; acdirmin %d; acdirmax %d\n",
                        nmp->nm_acregmin, nmp->nm_acregmax,
                        nmp->nm_acdirmin, nmp->nm_acdirmax);

        if (nfs_acdebug)
                kprintf("nfs_getattrcache: age = %d; final timeo = %d\n",
                        (int)(time_uptime - np->n_attrstamp), timeo);
#endif

        if (np->n_attrstamp == 0 || (time_uptime - np->n_attrstamp) >= timeo) {
                nfsstats.attrcache_misses++;
                return (ENOENT);
        }
        nfsstats.attrcache_hits++;

        /*
         * Our attribute cache can be stale due to modifications made on
         * this host.  XXX this is a bad hack.  We need a more deterministic
         * means of finding out which np fields are valid verses attr cache
         * fields.  We really should update the vattr info on the fly when
         * making local changes.
         */
        if (vap->va_size != np->n_size) {
                if (vap->va_type == VREG) {
                        if (np->n_flag & NLMODIFIED)
                                vap->va_size = np->n_size;
                        nfs_meta_setsize(vp, curthread, vap->va_size, 0);
                } else {
                        np->n_size = vap->va_size;
                }
        }
        bcopy((caddr_t)vap, (caddr_t)vaper, sizeof(struct vattr));
        if (np->n_flag & NCHG) {
                if (np->n_flag & NACC)
                        vaper->va_atime = np->n_atim;
                if (np->n_flag & NUPD)
                        vaper->va_mtime = np->n_mtim;
        }
        return (0);
}

#ifndef NFS_NOSERVER

/*
 * Set up nameidata for a lookup() call and do it.
 *
 * If pubflag is set, this call is done for a lookup operation on the
 * public filehandle. In that case we allow crossing mountpoints and
 * absolute pathnames. However, the caller is expected to check that
 * the lookup result is within the public fs, and deny access if
 * it is not.
 *
 * dirp may be set whether an error is returned or not, and must be 
 * released by the caller.
 *
 * On return nd->nl_nch usually points to the target ncp, which may represent
 * a negative hit.
 *
 * NOTE: the caller must call nlookup_done(nd) unconditionally on return
 * to cleanup.
 */
int
nfs_namei(struct nlookupdata *nd, struct ucred *cred, int nflags,
        struct vnode **dvpp, struct vnode **vpp,
        fhandle_t *fhp, int len,
        struct nfssvc_sock *slp, struct sockaddr *nam, struct mbuf **mdp,
        caddr_t *dposp, struct vnode **dirpp, struct thread *td,
        int kerbflag, int pubflag)
{
        int i, rem;
        struct mbuf *md;
        char *fromcp, *tocp, *cp;
        char *namebuf;
        struct nchandle nch;
        struct vnode *dp;
        struct mount *mp;
        int error, rdonly;

        namebuf = objcache_get(namei_oc, M_WAITOK);
        *dirpp = NULL;

        /*
         * Copy the name from the mbuf list to namebuf.
         */
        fromcp = *dposp;
        tocp = namebuf;
        md = *mdp;
        rem = mtod(md, caddr_t) + md->m_len - fromcp;
        for (i = 0; i < len; i++) {
                while (rem == 0) {
                        md = md->m_next;
                        if (md == NULL) {
                                error = EBADRPC;
                                goto out;
                        }
                        fromcp = mtod(md, caddr_t);
                        rem = md->m_len;
                }
                if (*fromcp == '\0' || (!pubflag && *fromcp == '/')) {
                        error = EACCES;
                        goto out;
                }
                *tocp++ = *fromcp++;
                rem--;
        }
        *tocp = '\0';
        *mdp = md;
        *dposp = fromcp;
        len = nfsm_rndup(len)-len;
        if (len > 0) {
                if (rem >= len)
                        *dposp += len;
                else if ((error = nfs_adv(mdp, dposp, len, rem)) != 0)
                        goto out;
        }

        /*
         * Extract and set starting directory.  The returned dp is refd
         * but not locked.
         */
        error = nfsrv_fhtovp(fhp, FALSE, &mp, &dp, cred, slp,
                                nam, &rdonly, kerbflag, pubflag);
        if (error)
                goto out;
        if (dp->v_type != VDIR) {
                vrele(dp);
                error = ENOTDIR;
                goto out;
        }

        /*
         * Set return directory.  Reference to dp is implicitly transfered 
         * to the returned pointer.  This must be set before we potentially
         * goto out below.
         */
        *dirpp = dp;

        /*
         * read-only - NLC_DELETE, NLC_RENAME_DST are disallowed.  NLC_CREATE
         *             is passed through to nlookup() and will be disallowed
         *             if the file does not already exist.
         */
        if (rdonly) {
                nflags |= NLC_NFS_RDONLY;
                if (nflags & (NLC_DELETE | NLC_RENAME_DST)) {
                        error = EROFS;
                        goto out;
                }
        }

        /*
         * Oh joy. For WebNFS, handle those pesky '%' escapes,
         * and the 'native path' indicator.
         */
        if (pubflag) {
                cp = objcache_get(namei_oc, M_WAITOK);
                fromcp = namebuf;
                tocp = cp;
                if ((unsigned char)*fromcp >= WEBNFS_SPECCHAR_START) {
                        switch ((unsigned char)*fromcp) {
                        case WEBNFS_NATIVE_CHAR:
                                /*
                                 * 'Native' path for us is the same
                                 * as a path according to the NFS spec,
                                 * just skip the escape char.
                                 */
                                fromcp++;
                                break;
                        /*
                         * More may be added in the future, range 0x80-0xff
                         */
                        default:
                                error = EIO;
                                objcache_put(namei_oc, cp);
                                goto out;
                        }
                }
                /*
                 * Translate the '%' escapes, URL-style.
                 */
                while (*fromcp != '\0') {
                        if (*fromcp == WEBNFS_ESC_CHAR) {
                                if (fromcp[1] != '\0' && fromcp[2] != '\0') {
                                        fromcp++;
                                        *tocp++ = HEXSTRTOI(fromcp);
                                        fromcp += 2;
                                        continue;
                                } else {
                                        error = ENOENT;
                                        objcache_put(namei_oc, cp);
                                        goto out;
                                }
                        } else
                                *tocp++ = *fromcp++;
                }
                *tocp = '\0';
                objcache_put(namei_oc, namebuf);
                namebuf = cp;
        }

        /*
         * Setup for search.  We need to get a start directory from dp.  Note
         * that dp is ref'd, but we no longer 'own' the ref (*dirpp owns it).
         */
        if (pubflag == 0) {
                nflags |= NLC_NFS_NOSOFTLINKTRAV;
                nflags |= NLC_NOCROSSMOUNT;
        }

        /*
         * We need a starting ncp from the directory vnode dp.  dp must not
         * be locked.  The returned ncp will be refd but not locked. 
         *
         * If no suitable ncp is found we instruct cache_fromdvp() to create
         * one.  If this fails the directory has probably been removed while
         * the target was chdir'd into it and any further lookup will fail.
         */
        if ((error = cache_fromdvp(dp, cred, 1, &nch)) != 0)
                goto out;
        nlookup_init_raw(nd, namebuf, UIO_SYSSPACE, nflags, cred, &nch);
        cache_drop(&nch);

        /*
         * Ok, do the lookup.
         */
        error = nlookup(nd);

        /*
         * If no error occured return the requested dvpp and vpp.  If
         * NLC_CREATE was specified nd->nl_nch may represent a negative
         * cache hit in which case we do not attempt to obtain the vp.
         */
        if (error == 0) {
                if (dvpp) {
                        if (nd->nl_nch.ncp->nc_parent) {
                                nch = nd->nl_nch;
                                nch.ncp = nch.ncp->nc_parent;
                                cache_hold(&nch);
                                cache_lock(&nch);
                                error = cache_vget(&nch, nd->nl_cred,
                                                   LK_EXCLUSIVE, dvpp);
                                cache_put(&nch);
                        } else {
                                error = ENXIO;
                        }
                }
                if (vpp && nd->nl_nch.ncp->nc_vp) {
                        error = cache_vget(&nd->nl_nch, nd->nl_cred, LK_EXCLUSIVE, vpp);
                }
                if (error) {
                        if (dvpp && *dvpp) {
                                vput(*dvpp);
                                *dvpp = NULL;
                        }
                        if (vpp && *vpp) {
                                vput(*vpp);
                                *vpp = NULL;
                        }
                }
        }

        /*
         * Finish up.
         */
out:
        objcache_put(namei_oc, namebuf);
        return (error);
}

/*
 * nfsrv_fhtovp() - convert a fh to a vnode ptr (optionally locked)
 *      - look up fsid in mount list (if not found ret error)
 *      - get vp and export rights by calling VFS_FHTOVP()
 *      - if cred->cr_uid == 0 or MNT_EXPORTANON set it to credanon
 *      - if not lockflag unlock it with vn_unlock()
 */
int
nfsrv_fhtovp(fhandle_t *fhp, int lockflag,
             struct mount **mpp, struct vnode **vpp,
             struct ucred *cred, struct nfssvc_sock *slp, struct sockaddr *nam,
             int *rdonlyp, int kerbflag, int pubflag)
{
        struct mount *mp;
        int i;
        struct ucred *credanon;
        int error, exflags;
#ifdef MNT_EXNORESPORT          /* XXX needs mountd and /etc/exports help yet */
        struct sockaddr_int *saddr;
#endif

        *vpp = NULL;
        *mpp = NULL;

        if (nfs_ispublicfh(fhp)) {
                if (!pubflag || !nfs_pub.np_valid)
                        return (ESTALE);
                fhp = &nfs_pub.np_handle;
        }

        mp = *mpp = vfs_getvfs(&fhp->fh_fsid);
        if (mp == NULL)
                return (ESTALE);
        error = VFS_CHECKEXP(mp, nam, &exflags, &credanon);
        if (error)
                return (error); 
        error = VFS_FHTOVP(mp, NULL, &fhp->fh_fid, vpp);
        if (error)
                return (ESTALE);
#ifdef MNT_EXNORESPORT
        if (!(exflags & (MNT_EXNORESPORT|MNT_EXPUBLIC))) {
                saddr = (struct sockaddr_in *)nam;
                if (saddr->sin_family == AF_INET &&
                    ntohs(saddr->sin_port) >= IPPORT_RESERVED) {
                        vput(*vpp);
                        *vpp = NULL;
                        return (NFSERR_AUTHERR | AUTH_TOOWEAK);
                }
        }
#endif
        /*
         * Check/setup credentials.
         */
        if (exflags & MNT_EXKERB) {
                if (!kerbflag) {
                        vput(*vpp);
                        *vpp = NULL;
                        return (NFSERR_AUTHERR | AUTH_TOOWEAK);
                }
        } else if (kerbflag) {
                vput(*vpp);
                *vpp = NULL;
                return (NFSERR_AUTHERR | AUTH_TOOWEAK);
        } else if (cred->cr_uid == 0 || (exflags & MNT_EXPORTANON)) {
                cred->cr_uid = credanon->cr_uid;
                for (i = 0; i < credanon->cr_ngroups && i < NGROUPS; i++)
                        cred->cr_groups[i] = credanon->cr_groups[i];
                cred->cr_ngroups = i;
        }
        if (exflags & MNT_EXRDONLY)
                *rdonlyp = 1;
        else
                *rdonlyp = 0;

        if (!lockflag)
                vn_unlock(*vpp);
        return (0);
}

/*
 * WebNFS: check if a filehandle is a public filehandle. For v3, this
 * means a length of 0, for v2 it means all zeroes. nfsm_srvmtofh has
 * transformed this to all zeroes in both cases, so check for it.
 */
int
nfs_ispublicfh(fhandle_t *fhp)
{
        char *cp = (char *)fhp;
        int i;

        for (i = 0; i < NFSX_V3FH; i++)
                if (*cp++ != 0)
                        return (FALSE);
        return (TRUE);
}
  
#endif /* NFS_NOSERVER */
/*
 * This function compares two net addresses by family and returns TRUE
 * if they are the same host.
 * If there is any doubt, return FALSE.
 * The AF_INET family is handled as a special case so that address mbufs
 * don't need to be saved to store "struct in_addr", which is only 4 bytes.
 */
int
netaddr_match(int family, union nethostaddr *haddr, struct sockaddr *nam)
{
        struct sockaddr_in *inetaddr;

        switch (family) {
        case AF_INET:
                inetaddr = (struct sockaddr_in *)nam;
                if (inetaddr->sin_family == AF_INET &&
                    inetaddr->sin_addr.s_addr == haddr->had_inetaddr)
                        return (1);
                break;
        default:
                break;
        }
        return (0);
}

static nfsuint64 nfs_nullcookie = { { 0, 0 } };
/*
 * This function finds the directory cookie that corresponds to the
 * logical byte offset given.
 */
nfsuint64 *
nfs_getcookie(struct nfsnode *np, off_t off, int add)
{
        struct nfsdmap *dp, *dp2;
        int pos;

        pos = (uoff_t)off / NFS_DIRBLKSIZ;
        if (pos == 0 || off < 0) {
#ifdef DIAGNOSTIC
                if (add)
                        panic("nfs getcookie add at <= 0");
#endif
                return (&nfs_nullcookie);
        }
        pos--;
        dp = np->n_cookies.lh_first;
        if (!dp) {
                if (add) {
                        dp = kmalloc(sizeof(struct nfsdmap), M_NFSDIROFF,
                                     M_WAITOK);
                        dp->ndm_eocookie = 0;
                        LIST_INSERT_HEAD(&np->n_cookies, dp, ndm_list);
                } else
                        return (NULL);
        }
        while (pos >= NFSNUMCOOKIES) {
                pos -= NFSNUMCOOKIES;
                if (dp->ndm_list.le_next) {
                        if (!add && dp->ndm_eocookie < NFSNUMCOOKIES &&
                                pos >= dp->ndm_eocookie)
                                return (NULL);
                        dp = dp->ndm_list.le_next;
                } else if (add) {
                        dp2 = kmalloc(sizeof(struct nfsdmap), M_NFSDIROFF,
                                      M_WAITOK);
                        dp2->ndm_eocookie = 0;
                        LIST_INSERT_AFTER(dp, dp2, ndm_list);
                        dp = dp2;
                } else
                        return (NULL);
        }
        if (pos >= dp->ndm_eocookie) {
                if (add)
                        dp->ndm_eocookie = pos + 1;
                else
                        return (NULL);
        }
        return (&dp->ndm_cookies[pos]);
}

/*
 * Invalidate cached directory information, except for the actual directory
 * blocks (which are invalidated separately).
 * Done mainly to avoid the use of stale offset cookies.
 */
void
nfs_invaldir(struct vnode *vp)
{
        struct nfsnode *np = VTONFS(vp);

#ifdef DIAGNOSTIC
        if (vp->v_type != VDIR)
                panic("nfs: invaldir not dir");
#endif
        np->n_direofoffset = 0;
        np->n_cookieverf.nfsuquad[0] = 0;
        np->n_cookieverf.nfsuquad[1] = 0;
        if (np->n_cookies.lh_first)
                np->n_cookies.lh_first->ndm_eocookie = 0;
}

/*
 * Set the v_type field for an NFS client's vnode and initialize for
 * buffer cache operations if necessary.
 */
void
nfs_setvtype(struct vnode *vp, enum vtype vtyp)
{
        vp->v_type = vtyp;

        switch(vtyp) {
        case VREG:
        case VDIR:
        case VLNK:
                /*
                 * Needs VMIO, size not yet known, and blocksize
                 * is not really relevant if we are passing a
                 * filesize of 0.
                 */
                vinitvmio(vp, 0, PAGE_SIZE, -1);
                break;
        default:
                break;
        }
}

/*
 * The write verifier has changed (probably due to a server reboot), so all
 * B_NEEDCOMMIT blocks will have to be written again. Since they are on the
 * dirty block list as B_DELWRI, all this takes is clearing the B_NEEDCOMMIT
 * and B_CLUSTEROK flags.  Once done the new write verifier can be set for the
 * mount point.
 *
 * B_CLUSTEROK must be cleared along with B_NEEDCOMMIT because stage 1 data 
 * writes are not clusterable.
 */

static int nfs_clearcommit_bp(struct buf *bp, void *data __unused);
static int nfs_clearcommit_callback(struct mount *mp, struct vnode *vp,
                                    void *data __unused);

void
nfs_clearcommit(struct mount *mp)
{
        vsyncscan(mp, VMSC_NOWAIT, nfs_clearcommit_callback, NULL);
}

static int
nfs_clearcommit_callback(struct mount *mp, struct vnode *vp,
                         void *data __unused)
{
        lwkt_gettoken(&vp->v_token);
        RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL,
                nfs_clearcommit_bp, NULL);
        lwkt_reltoken(&vp->v_token);

        return(0);
}

static int
nfs_clearcommit_bp(struct buf *bp, void *data __unused)
{
        if (BUF_REFCNT(bp) == 0 &&
            (bp->b_flags & (B_DELWRI | B_NEEDCOMMIT))
             == (B_DELWRI | B_NEEDCOMMIT)) {
                bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
        }
        return(0);
}

#ifndef NFS_NOSERVER
/*
 * Map errnos to NFS error numbers. For Version 3 also filter out error
 * numbers not specified for the associated procedure.
 */
int
nfsrv_errmap(struct nfsrv_descript *nd, int err)
{
        short *defaulterrp, *errp;

        if (nd->nd_flag & ND_NFSV3) {
            if (nd->nd_procnum <= NFSPROC_COMMIT) {
                errp = defaulterrp = nfsrv_v3errmap[nd->nd_procnum];
                while (*++errp) {
                        if (*errp == err)
                                return (err);
                        else if (*errp > err)
                                break;
                }
                return ((int)*defaulterrp);
            } else
                return (err & 0xffff);
        }
        if (err <= ELAST)
                return ((int)nfsrv_v2errmap[err - 1]);
        return (NFSERR_IO);
}

/*
 * Sort the group list in increasing numerical order.
 * (Insertion sort by Chris Torek, who was grossed out by the bubble sort
 *  that used to be here.)
 */
void
nfsrvw_sort(gid_t *list, int num)
{
        int i, j;
        gid_t v;

        /* Insertion sort. */
        for (i = 1; i < num; i++) {
                v = list[i];
                /* find correct slot for value v, moving others up */
                for (j = i; --j >= 0 && v < list[j];)
                        list[j + 1] = list[j];
                list[j + 1] = v;
        }
}

/*
 * copy credentials making sure that the result can be compared with bcmp().
 */
void
nfsrv_setcred(struct ucred *incred, struct ucred *outcred)
{
        int i;

        bzero((caddr_t)outcred, sizeof (struct ucred));
        outcred->cr_ref = 1;
        outcred->cr_uid = incred->cr_uid;
        outcred->cr_ngroups = incred->cr_ngroups;
        for (i = 0; i < incred->cr_ngroups; i++)
                outcred->cr_groups[i] = incred->cr_groups[i];
        nfsrvw_sort(outcred->cr_groups, outcred->cr_ngroups);
}
#endif /* NFS_NOSERVER */