[dragonfly.git] / sys / vfs / gnu / ext2fs / ext2_vnops.c

/*
 *  modified for EXT2FS support in Lites 1.1
 *
 *  Aug 1995, Godmar Back (gback@cs.utah.edu)
 *  University of Utah, Department of Computer Science
 */
/*
 * Copyright (c) 1982, 1986, 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * 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.
 *
 *      @(#)ufs_vnops.c 8.27 (Berkeley) 5/27/95
 *      @(#)ext2_vnops.c        8.7 (Berkeley) 2/3/94
 * $FreeBSD: src/sys/gnu/ext2fs/ext2_vnops.c,v 1.51.2.2 2003/01/02 17:26:18 bde Exp $
 * $DragonFly: src/sys/vfs/gnu/ext2fs/ext2_vnops.c,v 1.43 2008/06/19 23:27:39 dillon Exp $
 */

#include "opt_quota.h"
#include "opt_suiddir.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/resourcevar.h>
#include <sys/kernel.h>
#include <sys/stat.h>
#include <sys/fcntl.h>
#include <sys/buf.h>
#include <sys/stat.h>
#include <sys/proc.h>
#include <sys/priv.h>
#include <sys/mount.h>
#include <sys/time.h>
#include <sys/vnode.h>
#include <sys/dirent.h>
#include <sys/lockf.h>
#include <sys/event.h>
#include <sys/conf.h>
#include <sys/file.h>
#include <sys/jail.h>
#include <sys/namei.h>
#include <sys/signalvar.h>
#include <sys/unistd.h>

#include <vm/vm.h>
#include <vm/vm_extern.h>
#include <vm/vm_zone.h>
#include <vm/vnode_pager.h>

#include <sys/buf2.h>
#include <sys/thread2.h>

#include <vfs/fifofs/fifo.h>

#include "dir.h"
#include "quota.h"
#include "inode.h"
#include "ext2mount.h"
#include "ext2_fs_sb.h"
#include "fs.h"
#include "ext2_extern.h"
#include "ext2_fs.h"

static int ext2_access (struct vop_access_args *);
static int ext2_advlock (struct vop_advlock_args *);
static int ext2_chmod (struct vnode *, int, struct ucred *);
static int ext2_chown (struct vnode *, uid_t, gid_t, struct ucred *);
static int ext2_close (struct vop_close_args *);
static int ext2_getattr (struct vop_getattr_args *);
static int ext2_makeinode (int mode, struct vnode *, struct vnode **, struct componentname *);
static int ext2_mmap (struct vop_mmap_args *);
static int ext2_open (struct vop_open_args *);
static int ext2_pathconf (struct vop_pathconf_args *);
static int ext2_print (struct vop_print_args *);
static int ext2_readlink (struct vop_readlink_args *);
static int ext2_setattr (struct vop_setattr_args *);
static int ext2_strategy (struct vop_strategy_args *);
static int ext2_whiteout (struct vop_old_whiteout_args *);
static int filt_ext2read (struct knote *kn, long hint);
static int filt_ext2write (struct knote *kn, long hint);
static int filt_ext2vnode (struct knote *kn, long hint);
static void filt_ext2detach (struct knote *kn);
static int ext2_kqfilter (struct vop_kqfilter_args *ap);
static int ext2fifo_close (struct vop_close_args *);
static int ext2fifo_kqfilter (struct vop_kqfilter_args *);
static int ext2fifo_read (struct vop_read_args *);
static int ext2fifo_write (struct vop_write_args *);

static int ext2_fsync (struct vop_fsync_args *);
static int ext2_read (struct vop_read_args *);
static int ext2_write (struct vop_write_args *);
static int ext2_remove (struct vop_old_remove_args *);
static int ext2_link (struct vop_old_link_args *);
static int ext2_rename (struct vop_old_rename_args *);
static int ext2_mkdir (struct vop_old_mkdir_args *);
static int ext2_rmdir (struct vop_old_rmdir_args *);
static int ext2_create (struct vop_old_create_args *);
static int ext2_mknod (struct vop_old_mknod_args *);
static int ext2_symlink (struct vop_old_symlink_args *);

#include "ext2_readwrite.c"

union _qcvt {
        int64_t qcvt;
        int32_t val[2];
};
#define SETHIGH(q, h) { \
        union _qcvt tmp; \
        tmp.qcvt = (q); \
        tmp.val[_QUAD_HIGHWORD] = (h); \
        (q) = tmp.qcvt; \
}
#define SETLOW(q, l) { \
        union _qcvt tmp; \
        tmp.qcvt = (q); \
        tmp.val[_QUAD_LOWWORD] = (l); \
        (q) = tmp.qcvt; \
}
#define VN_KNOTE(vp, b) \
        KNOTE(&vp->v_pollinfo.vpi_selinfo.si_note, (b))

#define OFSFMT(vp)              ((vp)->v_mount->mnt_maxsymlinklen <= 0)

/*
 * A virgin directory (no blushing please).
 * Note that the type and namlen fields are reversed relative to ufs.
 * Also, we don't use `struct odirtemplate', since it would just cause
 * endianness problems.
 */
static struct dirtemplate ext2_mastertemplate = {
        0, 12, 1, EXT2_FT_DIR, ".",
        0, DIRBLKSIZ - 12, 2, EXT2_FT_DIR, ".."
};
static struct dirtemplate ext2_omastertemplate = {
        0, 12, 1, EXT2_FT_UNKNOWN, ".",
        0, DIRBLKSIZ - 12, 2, EXT2_FT_UNKNOWN, ".."
};

/*
 * Create a regular file
 *
 * ext2_create(struct vnode *a_dvp, struct vnode **a_vpp,
 *             struct componentname *a_cnp, struct vattr *a_vap)
 */
static int
ext2_create(struct vop_old_create_args *ap)
{
        int error;

        error =
            ext2_makeinode(MAKEIMODE(ap->a_vap->va_type, ap->a_vap->va_mode),
            ap->a_dvp, ap->a_vpp, ap->a_cnp);
        if (error)
                return (error);
        return (0);
}

/*
 * Synch an open file.
 *
 * ext2_fsync(struct vnode *a_vp, struct ucred *a_cred, int a_waitfor,
 *            struct proc *a_p)
 */
/* ARGSUSED */

static int ext2_fsync_bp(struct buf *bp, void *data);

struct ext2_fsync_bp_info {
        struct vnode *vp;
        int waitfor;
};

static int
ext2_fsync(struct vop_fsync_args *ap)
{
        struct ext2_fsync_bp_info info;
        struct vnode *vp = ap->a_vp;
        lwkt_tokref vlock;
        int count;

        /* 
         * XXX why is all this fs specific?
         */

        /*
         * Flush all dirty buffers associated with a vnode.
         */
        ext2_discard_prealloc(VTOI(vp));

        lwkt_gettoken(&vlock, &vp->v_token);
        info.vp = vp;
loop:
        info.waitfor = ap->a_waitfor;
        count = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL, 
                        ext2_fsync_bp, &info);
        if (count)
                goto loop;

        if (ap->a_waitfor == MNT_WAIT) {
                bio_track_wait(&vp->v_track_write, 0, 0);
#if DIAGNOSTIC
                if (!RB_EMPTY(&vp->v_rbdirty_tree)) {
                        vprint("ext2_fsync: dirty", vp);
                        goto loop;
                }
#endif
        }
        lwkt_reltoken(&vlock);
        return (EXT2_UPDATE(ap->a_vp, ap->a_waitfor == MNT_WAIT));
}

static int
ext2_fsync_bp(struct buf *bp, void *data)
{
        struct ext2_fsync_bp_info *info = data;

        if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT))
                return(0);
        if ((bp->b_flags & B_DELWRI) == 0)
                panic("ext2_fsync: not dirty");
        bremfree(bp);

        /*
         * Wait for I/O associated with indirect blocks to complete,
         * since there is no way to quickly wait for them below.
         */
        if (bp->b_vp == info->vp || info->waitfor == MNT_NOWAIT)
                bawrite(bp);
        else
                bwrite(bp);
        return(1);
}

/*
 * Mknod vnode call
 *
 * ext2_mknod(struct vnode *a_dvp, struct vnode **a_vpp,
 *            struct componentname *a_cnp, struct vattr *a_vap)
 */
/* ARGSUSED */
static int
ext2_mknod(struct vop_old_mknod_args *ap)
{
        struct vattr *vap = ap->a_vap;
        struct vnode **vpp = ap->a_vpp;
        struct inode *ip;
        ino_t ino;
        int error;

        if (vap->va_rmajor != VNOVAL &&
            makeudev(vap->va_rmajor, vap->va_rminor) == NOUDEV) {
                return (EINVAL);
        }

        error = ext2_makeinode(MAKEIMODE(vap->va_type, vap->va_mode),
            ap->a_dvp, vpp, ap->a_cnp);
        if (error)
                return (error);
        ip = VTOI(*vpp);
        ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
        if (vap->va_rmajor != VNOVAL) {
                /*
                 * Want to be able to use this to make badblock
                 * inodes, so don't truncate the dev number.
                 */
                ip->i_rdev = makeudev(vap->va_rmajor, vap->va_rminor);
        }
        /*
         * Remove inode, then reload it through VFS_VGET so it is
         * checked to see if it is an alias of an existing entry in
         * the inode cache.
         */
        (*vpp)->v_type = VNON;
        ino = ip->i_number;     /* Save this before vgone() invalidates ip. */
        vgone_vxlocked(*vpp);
        vput(*vpp);
        error = VFS_VGET(ap->a_dvp->v_mount, NULL, ino, vpp);
        if (error) {
                *vpp = NULL;
                return (error);
        }
        return (0);
}

/*
 * ext2_remove(struct vnode *a_dvp, struct vnode *a_vp,
 *             struct componentname *a_cnp)
 */
static int
ext2_remove(struct vop_old_remove_args *ap)
{
        struct inode *ip;
        struct vnode *vp = ap->a_vp;
        struct vnode *dvp = ap->a_dvp;
        int error;

        ip = VTOI(vp);
        if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
            (VTOI(dvp)->i_flags & APPEND)) {
                error = EPERM;
                goto out;
        }
        error = ext2_dirremove(dvp, ap->a_cnp);
        if (error == 0) {
                ip->i_nlink--;
                ip->i_flag |= IN_CHANGE;
        }
out:
        return (error);
}

/*
 * link vnode call
 *
 * ext2_link(struct vnode *a_tdvp, struct vnode *a_vp,
 *           struct componentname *a_cnp)
 */
static int
ext2_link(struct vop_old_link_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct vnode *tdvp = ap->a_tdvp;
        struct componentname *cnp = ap->a_cnp;
        struct inode *ip;
        int error;

        if (tdvp->v_mount != vp->v_mount) {
                error = EXDEV;
                goto out2;
        }
        if (tdvp != vp && (error = vn_lock(vp, LK_EXCLUSIVE))) {
                goto out2;
        }
        ip = VTOI(vp);
        if ((nlink_t)ip->i_nlink >= LINK_MAX) {
                error = EMLINK;
                goto out1;
        }
        if (ip->i_flags & (IMMUTABLE | APPEND)) {
                error = EPERM;
                goto out1;
        }
        ip->i_nlink++;
        ip->i_flag |= IN_CHANGE;
        error = EXT2_UPDATE(vp, 1);
        if (!error)
                error = ext2_direnter(ip, tdvp, cnp);
        if (error) {
                ip->i_nlink--;
                ip->i_flag |= IN_CHANGE;
        }
out1:
        if (tdvp != vp)
                vn_unlock(vp);
out2:
        return (error);
}

/*
 * Rename system call.  fdvp, fvp are ref'd.  tvp, tdvp are ref'd and locked.
 * all vp's are released and must be in an unlocked state on return.
 *
 * ext2_rename(struct vnode *a_fdvp, struct vnode *a_fvp,
 *              struct componentname *a_fcnp, struct vnode *a_tdvp,
 *              struct vnode *a_tvp, struct componentname *a_tcnp)
 */
static int
ext2_rename(struct vop_old_rename_args *ap)
{
        struct vnode *tvp = ap->a_tvp;
        struct vnode *tdvp = ap->a_tdvp;
        struct vnode *fvp = ap->a_fvp;
        struct vnode *fdvp = ap->a_fdvp;
        struct componentname *tcnp = ap->a_tcnp;
        struct componentname *fcnp = ap->a_fcnp;
        struct inode *ip, *xp, *dp;
        struct dirtemplate dirbuf;
        int doingdirectory = 0, oldparent = 0, newparent = 0;
        int error = 0;
        u_char namlen;

        /*
         * Check for cross-device rename.
         */
        if ((fvp->v_mount != tdvp->v_mount) ||
            (tvp && (fvp->v_mount != tvp->v_mount)) ||
            tvp == tdvp) {
                error = EXDEV;
abortit:
                if (tdvp == tvp)
                        vrele(tdvp);
                else
                        vput(tdvp);
                if (tvp)
                        vput(tvp);
                vrele(fdvp);
                vrele(fvp);
                return (error);
        }

        if (tvp && ((VTOI(tvp)->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
            (VTOI(tdvp)->i_flags & APPEND))) {
                error = EPERM;
                goto abortit;
        }

        /*
         * Renaming a file to itself has no effect.  The upper layers should
         * not call us in that case.  Temporarily just warn if they do.
         */
        if (fvp == tvp) {
                error = 0;
                goto abortit;
        }

        if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0)
                goto abortit;

        /*
         * fvp, tvp, tdvp locked.  fdvp not locked but note that fdvp may
         * be equal to tdvp.
         */
        dp = VTOI(fdvp);
        ip = VTOI(fvp);
        if (ip->i_nlink >= LINK_MAX) {
                vn_unlock(fvp);
                error = EMLINK;
                goto abortit;
        }
        if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))
            || (dp->i_flags & APPEND)) {
                vn_unlock(fvp);
                error = EPERM;
                goto abortit;
        }
        if ((ip->i_mode & IFMT) == IFDIR) {
                /*
                 * Avoid ".", "..", and aliases of "." for obvious reasons.
                 */
                if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.') ||
                    dp == ip || (fcnp->cn_flags | tcnp->cn_flags) & CNP_ISDOTDOT ||
                    (ip->i_flag & IN_RENAME)) {
                        vn_unlock(fvp);
                        error = EINVAL;
                        goto abortit;
                }
                ip->i_flag |= IN_RENAME;
                oldparent = dp->i_number;
                doingdirectory++;
        }

        /*
         * tvp is non-NULL if the target exists.   fvp is still locked but
         * we will unlock it soon.  The 'bad' goto target requires dp and
         * xp to be correctly assigned.
         */
        dp = VTOI(tdvp);
        if (tvp)
                xp = VTOI(tvp);
        else
                xp = NULL;

        /*
         * 1) Bump link count while we're moving stuff
         *    around.  If we crash somewhere before
         *    completing our work, the link count
         *    may be wrong, but correctable.
         */
        ip->i_nlink++;
        ip->i_flag |= IN_CHANGE;
        if ((error = EXT2_UPDATE(fvp, 1)) != 0) {
                vn_unlock(fvp);
                goto bad;
        }

        /*
         * If ".." must be changed (ie the directory gets a new
         * parent) then the source directory must not be in the
         * directory heirarchy above the target, as this would
         * orphan everything below the source directory. Also
         * the user must have write permission in the source so
         * as to be able to change "..". We must repeat the call
         * to namei, as the parent directory is unlocked by the
         * call to checkpath().
         */
        error = VOP_EACCESS(fvp, VWRITE, tcnp->cn_cred);
        vn_unlock(fvp);

        /*
         * tvp (if not NULL) and tdvp are locked.  fvp and fdvp are not.
         * dp and xp are set according to tdvp and tvp.
         */
        if (oldparent != dp->i_number)
                newparent = dp->i_number;
        if (doingdirectory && newparent) {
                if (error)      /* write access check above */
                        goto bad;

                /*
                 * Prepare for relookup, get rid of xp
                 */
                if (xp != NULL) {
                        vput(tvp);
                        xp = NULL;
                }

                /*
                 * checkpath vput()'s tdvp (VTOI(dp)) on return no matter what,
                 * get an extra ref so we wind up with just an unlocked, ref'd
                 * tdvp.  The 'out' target skips xp and tdvp cleanups.  Our
                 * tdvp is now unlocked so we have to clean it up ourselves.
                 */
                vref(tdvp);
                error = ext2_checkpath(ip, dp, tcnp->cn_cred);
                tcnp->cn_flags |= CNP_PDIRUNLOCK;
                if (error) {
                        vrele(tdvp);
                        goto out;
                }
                /*
                 * relookup no longer messes with the ref count.  An unlocked
                 * tdvp must be passed and if no error occurs a locked tdvp
                 * will be returned.  We have to use the out target again.
                 */
                error = relookup(tdvp, &tvp, tcnp);
                if (error) {
                        if (tcnp->cn_flags & CNP_PDIRUNLOCK)
                                vrele(tdvp);
                        else
                                vput(tdvp);
                        goto out;
                }

                /*
                 * tdvp is locked at this point.  in the RENAME case tvp may
                 * be NULL without an error, assign xp accordingly.  The
                 * 'bad' target can be used again after this.
                 */
                dp = VTOI(tdvp);
                if (tvp)
                        xp = VTOI(tvp);
        }
        /*
         * 2) If target doesn't exist, link the target
         *    to the source and unlink the source.
         *    Otherwise, rewrite the target directory
         *    entry to reference the source inode and
         *    expunge the original entry's existence.
         *
         * tdvp and tvp are cleaned up by this code.  tvp is only good if
         * xp is not NULL.
         */
        if (xp == NULL) {
                if (dp->i_dev != ip->i_dev)
                        panic("ext2_rename: EXDEV");
                /*
                 * Account for ".." in new directory.
                 * When source and destination have the same
                 * parent we don't fool with the link count.
                 */
                if (doingdirectory && newparent) {
                        if ((nlink_t)dp->i_nlink >= LINK_MAX) {
                                error = EMLINK;
                                goto bad;
                        }
                        dp->i_nlink++;
                        dp->i_flag |= IN_CHANGE;
                        error = EXT2_UPDATE(tdvp, 1);
                        if (error)
                                goto bad;
                }
                error = ext2_direnter(ip, tdvp, tcnp);
                if (error) {
                        if (doingdirectory && newparent) {
                                dp->i_nlink--;
                                dp->i_flag |= IN_CHANGE;
                                EXT2_UPDATE(tdvp, 1);
                        }
                        goto bad;
                }

                /*
                 * manual cleanup, we can't use the bad or out target after
                 * this.
                 */
                vput(tdvp);
        } else {
                if (xp->i_dev != dp->i_dev || xp->i_dev != ip->i_dev)
                        panic("ext2_rename: EXDEV");
                /*
                 * Short circuit rename(foo, foo).
                 */
                if (xp->i_number == ip->i_number)
                        panic("ext2_rename: same file");
                /*
                 * If the parent directory is "sticky", then the user must
                 * own the parent directory, or the destination of the rename,
                 * otherwise the destination may not be changed (except by
                 * root). This implements append-only directories.
                 */
                if ((dp->i_mode & S_ISTXT) && tcnp->cn_cred->cr_uid != 0 &&
                    tcnp->cn_cred->cr_uid != dp->i_uid &&
                    xp->i_uid != tcnp->cn_cred->cr_uid) {
                        error = EPERM;
                        goto bad;
                }
                /*
                 * Target must be empty if a directory and have no links
                 * to it. Also, ensure source and target are compatible
                 * (both directories, or both not directories).
                 */
                if ((xp->i_mode&IFMT) == IFDIR) {
                        if (! ext2_dirempty(xp, dp->i_number, tcnp->cn_cred) || 
                            xp->i_nlink > 2) {
                                error = ENOTEMPTY;
                                goto bad;
                        }
                        if (!doingdirectory) {
                                error = ENOTDIR;
                                goto bad;
                        }
                } else if (doingdirectory) {
                        error = EISDIR;
                        goto bad;
                }
                error = ext2_dirrewrite(dp, ip, tcnp);
                if (error)
                        goto bad;
                /*
                 * If the target directory is in the same
                 * directory as the source directory,
                 * decrement the link count on the parent
                 * of the target directory.
                 */
                 if (doingdirectory && !newparent) {
                        dp->i_nlink--;
                        dp->i_flag |= IN_CHANGE;
                }

                /*
                 * manual cleanup, we can't use the bad or out target after
                 * this.
                 */
                vput(tdvp);

                /*
                 * Adjust the link count of the target to
                 * reflect the dirrewrite above.  If this is
                 * a directory it is empty and there are
                 * no links to it, so we can squash the inode and
                 * any space associated with it.  We disallowed
                 * renaming over top of a directory with links to
                 * it above, as the remaining link would point to
                 * a directory without "." or ".." entries.
                 */
                xp->i_nlink--;
                if (doingdirectory) {
                        if (--xp->i_nlink != 0)
                                panic("ext2_rename: linked directory");
                        error = EXT2_TRUNCATE(tvp, (off_t)0, IO_SYNC,
                                              tcnp->cn_cred);
                }
                xp->i_flag |= IN_CHANGE;
                vput(tvp);
                xp = NULL;
        }

        /*
         * tvp and tdvp have been cleaned up.  The bad and out targets may
         * not be used.  fvp and fdvp are ref'd but not locked.  ip
         * still represents the old fvp and ip->i_flag may still have IN_RENAME
         * set (if doingdirectory).
         */

        /*
         * 3) Unlink the source.
         *
         * fdvp is locked and ref'd. ap->a_fvp holds the old lookup unlocked
         * and ref'd, fvp will hold the new lookup locked and ref'd.
         *
         * After the relookup ap->a_fvp must be released as part of our
         * cleanup, not just fdvp and fvp.  And, on success, fdvp and
         * fvp will be locked so the bad and out targets cannot be used.
         */
        fcnp->cn_flags &= ~CNP_MODMASK;
        fcnp->cn_flags |= CNP_LOCKPARENT;
        KKASSERT(fcnp->cn_flags & CNP_PDIRUNLOCK);
        error = relookup(fdvp, &fvp, fcnp);
        if (error) {
                /*
                 * From name has disappeared.
                 */
                if (doingdirectory)
                        panic("ext2_rename: lost dir entry");
                /* ip->i_flag only sets IN_RENAME if doingdirectory */
                vrele(ap->a_fvp);
                if (fcnp->cn_flags & CNP_PDIRUNLOCK)
                        vrele(fdvp);
                else
                        vput(fdvp);
                return (0);
        }
        KKASSERT((fcnp->cn_flags & CNP_PDIRUNLOCK) == 0);

        /*
         * This case shouldn't occur
         */
        if (fvp == NULL) {
                /*
                 * From name has disappeared.
                 */
                if (doingdirectory)
                        panic("ext2_rename: lost dir entry");
                /* ip->i_flag only sets IN_RENAME if doingdirectory */
                vrele(ap->a_fvp);
                vput(fvp);
                vput(fdvp);
                return (0);
        }

        /*
         * fvp and fdvp are both ref'd and locked.
         */
        xp = VTOI(fvp);
        dp = VTOI(fdvp);

        /*
         * Ensure that the directory entry still exists and has not
         * changed while the new name has been entered. If the source is
         * a file then the entry may have been unlinked or renamed. In
         * either case there is no further work to be done. If the source
         * is a directory then it cannot have been rmdir'ed; its link
         * count of three would cause a rmdir to fail with ENOTEMPTY.
         * The IN_RENAME flag ensures that it cannot be moved by another
         * rename.
         */
        if (xp != ip) {
                if (doingdirectory)
                        panic("ext2_rename: lost dir entry");
                /* ip->i_flag only sets IN_RENAME if doingdirectory */
        } else {
                /*
                 * If the source is a directory with a
                 * new parent, the link count of the old
                 * parent directory must be decremented
                 * and ".." set to point to the new parent.
                 */
                if (doingdirectory && newparent) {
                        dp->i_nlink--;
                        dp->i_flag |= IN_CHANGE;
                        error = vn_rdwr(UIO_READ, fvp, (caddr_t)&dirbuf,
                                        sizeof (struct dirtemplate), (off_t)0,
                                        UIO_SYSSPACE, IO_NODELOCKED,
                                        tcnp->cn_cred, NULL);
                        if (error == 0) {
                                /* Like ext2 little-endian: */
                                namlen = dirbuf.dotdot_type;
                                if (namlen != 2 ||
                                    dirbuf.dotdot_name[0] != '.' ||
                                    dirbuf.dotdot_name[1] != '.') {
                                        ext2_dirbad(xp, (doff_t)12,
                                            "rename: mangled dir");
                                } else {
                                        dirbuf.dotdot_ino = newparent;
                                        vn_rdwr(UIO_WRITE, fvp,
                                                (caddr_t)&dirbuf,
                                                sizeof (struct dirtemplate),
                                                (off_t)0, UIO_SYSSPACE,
                                                IO_NODELOCKED|IO_SYNC,
                                                tcnp->cn_cred, NULL);
                                }
                        }
                }
                error = ext2_dirremove(fdvp, fcnp);
                if (!error) {
                        xp->i_nlink--;
                        xp->i_flag |= IN_CHANGE;
                }
                xp->i_flag &= ~IN_RENAME;
        }
        vput(fdvp);
        vput(fvp);
        vrele(ap->a_fvp);
        return (error);

bad:
        if (xp)
                vput(ITOV(xp));
        if (dp)
                vput(ITOV(dp));
out:
        if (doingdirectory)
                ip->i_flag &= ~IN_RENAME;
        if (vn_lock(fvp, LK_EXCLUSIVE) == 0) {
                ip->i_nlink--;
                ip->i_flag |= IN_CHANGE;
                ip->i_flag &= ~IN_RENAME;
                vput(fvp);
        } else {
                vrele(fvp);
        }
        return (error);
}

/*
 * Mkdir system call
 *
 * ext2_mkdir(struct vnode *a_dvp, struct vnode **a_vpp,
 *            struct componentname *a_cnp, struct vattr *a_vap)
 */
static int
ext2_mkdir(struct vop_old_mkdir_args *ap)
{
        struct vnode *dvp = ap->a_dvp;
        struct vattr *vap = ap->a_vap;
        struct componentname *cnp = ap->a_cnp;
        struct inode *ip, *dp;
        struct vnode *tvp;
        struct dirtemplate dirtemplate, *dtp;
        int error, dmode;

        dp = VTOI(dvp);
        if ((nlink_t)dp->i_nlink >= LINK_MAX) {
                error = EMLINK;
                goto out;
        }
        dmode = vap->va_mode & 0777;
        dmode |= IFDIR;
        /*
         * Must simulate part of ext2_makeinode here to acquire the inode,
         * but not have it entered in the parent directory. The entry is
         * made later after writing "." and ".." entries.
         */
        error = EXT2_VALLOC(dvp, dmode, cnp->cn_cred, &tvp);
        if (error)
                goto out;
        ip = VTOI(tvp);
        ip->i_gid = dp->i_gid;
#ifdef SUIDDIR
        {
#ifdef QUOTA
                struct ucred ucred, *ucp;
                ucp = cnp->cn_cred;
#endif
                /*
                 * if we are hacking owners here, (only do this where told to)
                 * and we are not giving it TOO root, (would subvert quotas)
                 * then go ahead and give it to the other user.
                 * The new directory also inherits the SUID bit. 
                 * If user's UID and dir UID are the same,
                 * 'give it away' so that the SUID is still forced on.
                 */
                if ( (dvp->v_mount->mnt_flag & MNT_SUIDDIR) &&
                   (dp->i_mode & ISUID) && dp->i_uid) {
                        dmode |= ISUID;
                        ip->i_uid = dp->i_uid;
#ifdef QUOTA
                        if (dp->i_uid != cnp->cn_cred->cr_uid) {
                                /*
                                 * make sure the correct user gets charged
                                 * for the space.
                                 * Make a dummy credential for the victim.
                                 * XXX This seems to never be accessed out of
                                 * our context so a stack variable is ok.
                                 */
                                ucred.cr_ref = 1;
                                ucred.cr_uid = ip->i_uid;
                                ucred.cr_ngroups = 1;
                                ucred.cr_groups[0] = dp->i_gid;
                                ucp = &ucred;
                        }
#endif
                } else {
                        ip->i_uid = cnp->cn_cred->cr_uid;
                }
#ifdef QUOTA
                if ((error = ext2_getinoquota(ip)) ||
                (error = ext2_chkiq(ip, 1, ucp, 0))) {
                        EXT2_VFREE(tvp, ip->i_number, dmode);
                        vput(tvp);
                        return (error);
                }
#endif
        }
#else
        ip->i_uid = cnp->cn_cred->cr_uid;
#ifdef QUOTA
        if ((error = ext2_getinoquota(ip)) ||
            (error = ext2_chkiq(ip, 1, cnp->cn_cred, 0))) {
                EXT2_VFREE(tvp, ip->i_number, dmode);
                vput(tvp);
                return (error);
        }
#endif
#endif
        ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
        ip->i_mode = dmode;
        tvp->v_type = VDIR;     /* Rest init'd in getnewvnode(). */
        ip->i_nlink = 2;
        if (cnp->cn_flags & CNP_ISWHITEOUT)
                ip->i_flags |= UF_OPAQUE;
        error = EXT2_UPDATE(tvp, 1);

        /*
         * The vnode must have a VM object in order to issue buffer cache
         * ops on it.
         */
        vinitvmio(tvp, 0);

        /*
         * Bump link count in parent directory
         * to reflect work done below.  Should
         * be done before reference is created
         * so reparation is possible if we crash.
         */
        dp->i_nlink++;
        dp->i_flag |= IN_CHANGE;
        error = EXT2_UPDATE(dvp, 1);
        if (error)
                goto bad;

        /* Initialize directory with "." and ".." from static template. */
        if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs->s_es,
            EXT2_FEATURE_INCOMPAT_FILETYPE))
                dtp = &ext2_mastertemplate;
        else
                dtp = &ext2_omastertemplate;
        dirtemplate = *dtp;
        dirtemplate.dot_ino = ip->i_number;
        dirtemplate.dotdot_ino = dp->i_number;
        /* note that in ext2 DIRBLKSIZ == blocksize, not DEV_BSIZE 
         * so let's just redefine it - for this function only
         */
#undef  DIRBLKSIZ 
#define DIRBLKSIZ  VTOI(dvp)->i_e2fs->s_blocksize
        dirtemplate.dotdot_reclen = DIRBLKSIZ - 12;
        error = vn_rdwr(UIO_WRITE, tvp, (caddr_t)&dirtemplate,
                        sizeof (dirtemplate), (off_t)0, UIO_SYSSPACE,
                        IO_NODELOCKED|IO_SYNC, cnp->cn_cred, NULL);
        if (error) {
                dp->i_nlink--;
                dp->i_flag |= IN_CHANGE;
                goto bad;
        }
        if (DIRBLKSIZ > VFSTOEXT2(dvp->v_mount)->um_mountp->mnt_stat.f_bsize)
                panic("ext2_mkdir: blksize"); /* XXX should grow with balloc() */
        else {
                ip->i_size = DIRBLKSIZ;
                ip->i_flag |= IN_CHANGE;
        }

        /* Directory set up, now install its entry in the parent directory. */
        error = ext2_direnter(ip, dvp, cnp);
        if (error) {
                dp->i_nlink--;
                dp->i_flag |= IN_CHANGE;
        }
bad:
        /*
         * No need to do an explicit VOP_TRUNCATE here, vrele will do this
         * for us because we set the link count to 0.
         */
        if (error) {
                ip->i_nlink = 0;
                ip->i_flag |= IN_CHANGE;
                vput(tvp);
        } else
                *ap->a_vpp = tvp;
out:
        return (error);
#undef  DIRBLKSIZ
#define DIRBLKSIZ  DEV_BSIZE
}

/*
 * Rmdir system call.
 *
 * ext2_rmdir(struct vnode *a_dvp, struct vnode *a_vp,
 *            struct componentname *a_cnp)
 */
static int
ext2_rmdir(struct vop_old_rmdir_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct vnode *dvp = ap->a_dvp;
        struct componentname *cnp = ap->a_cnp;
        struct inode *ip, *dp;
        int error;

        ip = VTOI(vp);
        dp = VTOI(dvp);

        /*
         * Verify the directory is empty (and valid).
         * (Rmdir ".." won't be valid since
         *  ".." will contain a reference to
         *  the current directory and thus be
         *  non-empty.)
         */
        error = 0;
        if (ip->i_nlink != 2 || !ext2_dirempty(ip, dp->i_number, cnp->cn_cred)) {
                error = ENOTEMPTY;
                goto out;
        }
        if ((dp->i_flags & APPEND)
            || (ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))) {
                error = EPERM;
                goto out;
        }
        /*
         * Delete reference to directory before purging
         * inode.  If we crash in between, the directory
         * will be reattached to lost+found,
         */
        error = ext2_dirremove(dvp, cnp);
        if (error)
                goto out;
        dp->i_nlink--;
        dp->i_flag |= IN_CHANGE;
        vn_unlock(dvp);
        /*
         * Truncate inode.  The only stuff left
         * in the directory is "." and "..".  The
         * "." reference is inconsequential since
         * we're quashing it.  The ".." reference
         * has already been adjusted above.  We've
         * removed the "." reference and the reference
         * in the parent directory, but there may be
         * other hard links so decrement by 2 and
         * worry about them later.
         */
        ip->i_nlink -= 2;
        error = EXT2_TRUNCATE(vp, (off_t)0, IO_SYNC, cnp->cn_cred);
        vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
out:
        return (error);
}

/*
 * symlink -- make a symbolic link
 *
 * ext2_symlink(struct vnode *a_dvp, struct vnode **a_vpp,
 *              struct componentname *a_cnp, struct vattr *a_vap,
 *              char *a_target)
 */
static int
ext2_symlink(struct vop_old_symlink_args *ap)
{
        struct vnode *vp, **vpp = ap->a_vpp;
        struct inode *ip;
        int len, error;

        error = ext2_makeinode(IFLNK | ap->a_vap->va_mode, ap->a_dvp,
            vpp, ap->a_cnp);
        if (error)
                return (error);
        vp = *vpp;
        len = strlen(ap->a_target);
        if (len < vp->v_mount->mnt_maxsymlinklen) {
                ip = VTOI(vp);
                bcopy(ap->a_target, (char *)ip->i_shortlink, len);
                ip->i_size = len;
                ip->i_flag |= IN_CHANGE | IN_UPDATE;
        } else {
                /*
                 * Make sure we have a VM object in order to use
                 * the buffer cache.
                 */
                if (vp->v_object == NULL)
                        vinitvmio(vp, 0);

                error = vn_rdwr(UIO_WRITE, vp, ap->a_target, len, (off_t)0,
                                UIO_SYSSPACE, IO_NODELOCKED, 
                                ap->a_cnp->cn_cred, NULL);

                if (error)
                        vput(vp);
        }

        return (error);
}

/*
 * Allocate a new inode.
 */
static int
ext2_makeinode(int mode, struct vnode *dvp, struct vnode **vpp,
               struct componentname *cnp)
{
        struct inode *ip, *pdir;
        struct vnode *tvp;
        int error;

        pdir = VTOI(dvp);
        *vpp = NULL;
        if ((mode & IFMT) == 0)
                mode |= IFREG;

        error = EXT2_VALLOC(dvp, mode, cnp->cn_cred, &tvp);
        if (error) {
                return (error);
        }
        ip = VTOI(tvp);
        ip->i_gid = pdir->i_gid;
#ifdef SUIDDIR
        {
#ifdef QUOTA
                struct ucred ucred, *ucp;
                ucp = cnp->cn_cred;
#endif
                /*
                 * if we are
                 * not the owner of the directory,
                 * and we are hacking owners here, (only do this where told to)
                 * and we are not giving it TOO root, (would subvert quotas)
                 * then go ahead and give it to the other user.
                 * Note that this drops off the execute bits for security.
                 */
                if ( (dvp->v_mount->mnt_flag & MNT_SUIDDIR) &&
                     (pdir->i_mode & ISUID) &&
                     (pdir->i_uid != cnp->cn_cred->cr_uid) && pdir->i_uid) {
                        ip->i_uid = pdir->i_uid;
                        mode &= ~07111;
#ifdef QUOTA
                        /*
                         * make sure the correct user gets charged
                         * for the space.
                         * Quickly knock up a dummy credential for the victim.
                         * XXX This seems to never be accessed out of our
                         * context so a stack variable is ok.
                         */
                        ucred.cr_ref = 1;
                        ucred.cr_uid = ip->i_uid;
                        ucred.cr_ngroups = 1;
                        ucred.cr_groups[0] = pdir->i_gid;
                        ucp = &ucred;
#endif
                } else {
                        ip->i_uid = cnp->cn_cred->cr_uid;
                }
        
#ifdef QUOTA
                if ((error = ext2_getinoquota(ip)) ||
                (error = ext2_chkiq(ip, 1, ucp, 0))) {
                        EXT2_VFREE(tvp, ip->i_number, mode);
                        vput(tvp);
                        return (error);
                }
#endif
        }
#else
        ip->i_uid = cnp->cn_cred->cr_uid;
#ifdef QUOTA
        if ((error = ext2_getinoquota(ip)) ||
            (error = ext2_chkiq(ip, 1, cnp->cn_cred, 0))) {
                EXT2_VFREE(tvp, ip->i_number, mode);
                vput(tvp);
                return (error);
        }
#endif
#endif
        ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
        ip->i_mode = mode;
        tvp->v_type = IFTOVT(mode);     /* Rest init'd in getnewvnode(). */
        ip->i_nlink = 1;
        if ((ip->i_mode & ISGID) && !groupmember(ip->i_gid, cnp->cn_cred) &&
            priv_check_cred(cnp->cn_cred, PRIV_VFS_SETGID, 0))
                ip->i_mode &= ~ISGID;

        if (cnp->cn_flags & CNP_ISWHITEOUT)
                ip->i_flags |= UF_OPAQUE;

        /*
         * Regular files and directories need VM objects.  Softlinks do 
         * not (not immediately anyway).
         */
        if (tvp->v_type == VREG || tvp->v_type == VDIR)
                vinitvmio(tvp, 0);

        /*
         * Make sure inode goes to disk before directory entry.
         */
        error = EXT2_UPDATE(tvp, 1);
        if (error)
                goto bad;
        error = ext2_direnter(ip, dvp, cnp);
        if (error)
                goto bad;

        *vpp = tvp;
        return (0);

bad:
        /*
         * Write error occurred trying to update the inode
         * or the directory so must deallocate the inode.
         */
        ip->i_nlink = 0;
        ip->i_flag |= IN_CHANGE;
        vput(tvp);
        return (error);
}

void
ext2_itimes(struct vnode *vp)
{
        struct inode *ip;
        struct timespec ts;

        ip = VTOI(vp);
        if ((ip->i_flag & (IN_ACCESS | IN_CHANGE | IN_UPDATE)) == 0)
                return;
        if ((vp->v_type == VBLK || vp->v_type == VCHR) && !DOINGSOFTDEP(vp))
                ip->i_flag |= IN_LAZYMOD;
        else
                ip->i_flag |= IN_MODIFIED;
        if ((vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
                vfs_timestamp(&ts);
                if (ip->i_flag & IN_ACCESS) {
                        ip->i_atime = ts.tv_sec;
                        ip->i_atimensec = ts.tv_nsec;
                }
                if (ip->i_flag & IN_UPDATE) {
                        ip->i_mtime = ts.tv_sec;
                        ip->i_mtimensec = ts.tv_nsec;
                        ip->i_modrev++;
                }
                if (ip->i_flag & IN_CHANGE) {
                        ip->i_ctime = ts.tv_sec;
                        ip->i_ctimensec = ts.tv_nsec;
                }
        }
        ip->i_flag &= ~(IN_ACCESS | IN_CHANGE | IN_UPDATE);
}

/*
 * Open called.
 *
 * Nothing to do.
 *
 * ext2_open(struct vnode *a_vp, int a_mode, struct ucred *a_cred,
 *           struct file *a_fp)
 */
/* ARGSUSED */
static
int
ext2_open(struct vop_open_args *ap)
{
        struct vnode *vp = ap->a_vp;

        /*
         * Files marked append-only must be opened for appending.
         */
        if ((VTOI(vp)->i_flags & APPEND) &&
            (ap->a_mode & (FWRITE | O_APPEND)) == FWRITE) {
                return (EPERM);
        }
        return (vop_stdopen(ap));
}

/*
 * Close called.
 *
 * Update the times on the inode.
 *
 * ext2_close(struct vnode *a_vp, int a_fflag, struct ucred *a_cred)
 */
/* ARGSUSED */
static
int
ext2_close(struct vop_close_args *ap)
{
        struct vnode *vp = ap->a_vp;

        if (vp->v_sysref.refcnt > 1)
                ext2_itimes(vp);
        return (vop_stdclose(ap));
}

/*
 * ext2_access(struct vnode *a_vp, int a_mode, struct ucred *a_cred)
 */
static
int
ext2_access(struct vop_access_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        int error;

#ifdef QUOTA
        if (ap->a_mode & VWRITE) {
                switch (vp->v_type) {
                case VDIR:
                case VLNK:
                case VREG:
                        if ((error = ext2_getinoquota(ip)) != 0)
                                return (error);
                        break;
                default:
                        break;
                }
        }
#endif

        error = vop_helper_access(ap, ip->i_uid, ip->i_gid, ip->i_mode,
                                  ip->i_flags);
        return (error);
}

/*
 * ext2_getattr(struct vnode *a_vp, struct vattr *a_vap)
 */
/* ARGSUSED */
static
int
ext2_getattr(struct vop_getattr_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        struct vattr *vap = ap->a_vap;

        ext2_itimes(vp);
        /*
         * Copy from inode table
         */
        vap->va_fsid = dev2udev(ip->i_dev);
        vap->va_fileid = ip->i_number;
        vap->va_mode = ip->i_mode & ~IFMT;
        vap->va_nlink = VFSTOEXT2(vp->v_mount)->um_i_effnlink_valid ?
            ip->i_effnlink : ip->i_nlink;
        vap->va_uid = ip->i_uid;
        vap->va_gid = ip->i_gid;
        vap->va_rmajor = umajor(ip->i_rdev);
        vap->va_rminor = uminor(ip->i_rdev);
        vap->va_size = ip->i_din.di_size;
        vap->va_atime.tv_sec = ip->i_atime;
        vap->va_atime.tv_nsec = ip->i_atimensec;
        vap->va_mtime.tv_sec = ip->i_mtime;
        vap->va_mtime.tv_nsec = ip->i_mtimensec;
        vap->va_ctime.tv_sec = ip->i_ctime;
        vap->va_ctime.tv_nsec = ip->i_ctimensec;
        vap->va_flags = ip->i_flags;
        vap->va_gen = ip->i_gen;
        vap->va_blocksize = vp->v_mount->mnt_stat.f_iosize;
        vap->va_bytes = dbtob((u_quad_t)ip->i_blocks);
        vap->va_type = IFTOVT(ip->i_mode);
        vap->va_filerev = ip->i_modrev;
        return (0);
}

/*
 * Set attribute vnode op. called from several syscalls
 *
 * ext2_setattr(struct vnode *a_vp, struct vattr *a_vap, struct ucred *a_cred)
 */
static
int
ext2_setattr(struct vop_setattr_args *ap)
{
        struct vattr *vap = ap->a_vap;
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        struct ucred *cred = ap->a_cred;
        int error;

        /*
         * Check for unsettable attributes.
         */
        if ((vap->va_type != VNON) || (vap->va_nlink != VNOVAL) ||
            (vap->va_fsid != VNOVAL) || (vap->va_fileid != VNOVAL) ||
            (vap->va_blocksize != VNOVAL) || (vap->va_rmajor != VNOVAL) ||
            ((int)vap->va_bytes != VNOVAL) || (vap->va_gen != VNOVAL)) {
                return (EINVAL);
        }
        if (vap->va_flags != VNOVAL) {
                if (vp->v_mount->mnt_flag & MNT_RDONLY)
                        return (EROFS);
                if (cred->cr_uid != ip->i_uid &&
                    (error = priv_check_cred(cred, PRIV_VFS_SETATTR, 0)))
                        return (error);
                /*
                 * Note that a root chflags becomes a user chflags when
                 * we are jailed, unless the jail.chflags_allowed sysctl
                 * is set.
                 */
                if (cred->cr_uid == 0 && 
                    (!jailed(cred) || jail_chflags_allowed)) {
                        if ((ip->i_flags
                            & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND)) &&
                            securelevel > 0)
                                return (EPERM);
                        ip->i_flags = vap->va_flags;
                } else {
                        if (ip->i_flags
                            & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND) ||
                            (vap->va_flags & UF_SETTABLE) != vap->va_flags)
                                return (EPERM);
                        ip->i_flags &= SF_SETTABLE;
                        ip->i_flags |= (vap->va_flags & UF_SETTABLE);
                }
                ip->i_flag |= IN_CHANGE;
                if (vap->va_flags & (IMMUTABLE | APPEND))
                        return (0);
        }
        if (ip->i_flags & (IMMUTABLE | APPEND))
                return (EPERM);
        /*
         * Go through the fields and update iff not VNOVAL.
         */
        if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
                if (vp->v_mount->mnt_flag & MNT_RDONLY)
                        return (EROFS);
                if ((error = ext2_chown(vp, vap->va_uid, vap->va_gid, cred)) != 0)
                        return (error);
        }
        if (vap->va_size != VNOVAL) {
                /*
                 * Disallow write attempts on read-only filesystems;
                 * unless the file is a socket, fifo, or a block or
                 * character device resident on the filesystem.
                 */
                switch (vp->v_type) {
                case VDIR:
                        return (EISDIR);
                case VLNK:
                case VREG:
                        if (vp->v_mount->mnt_flag & MNT_RDONLY)
                                return (EROFS);
                        break;
                default:
                        break;
                }
                if ((error = EXT2_TRUNCATE(vp, vap->va_size, 0, cred)) != 0)
                        return (error);
        }
        ip = VTOI(vp);
        if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
                if (vp->v_mount->mnt_flag & MNT_RDONLY)
                        return (EROFS);
                if (cred->cr_uid != ip->i_uid &&
                    (error = priv_check_cred(cred, PRIV_VFS_SETATTR, 0)) &&
                    ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
                    (error = VOP_EACCESS(vp, VWRITE, cred))))
                        return (error);
                if (vap->va_atime.tv_sec != VNOVAL)
                        ip->i_flag |= IN_ACCESS;
                if (vap->va_mtime.tv_sec != VNOVAL)
                        ip->i_flag |= IN_CHANGE | IN_UPDATE;
                ext2_itimes(vp);
                if (vap->va_atime.tv_sec != VNOVAL) {
                        ip->i_atime = vap->va_atime.tv_sec;
                        ip->i_atimensec = vap->va_atime.tv_nsec;
                }
                if (vap->va_mtime.tv_sec != VNOVAL) {
                        ip->i_mtime = vap->va_mtime.tv_sec;
                        ip->i_mtimensec = vap->va_mtime.tv_nsec;
                }
                error = EXT2_UPDATE(vp, 0);
                if (error)
                        return (error);
        }
        error = 0;
        if (vap->va_mode != (mode_t)VNOVAL) {
                if (vp->v_mount->mnt_flag & MNT_RDONLY)
                        return (EROFS);
                error = ext2_chmod(vp, (int)vap->va_mode, cred);
        }
        VN_KNOTE(vp, NOTE_ATTRIB);
        return (error);
}

/*
 * Change the mode on a file.
 * Inode must be locked before calling.
 */
static int
ext2_chmod(struct vnode *vp, int mode, struct ucred *cred)
{
        struct inode *ip = VTOI(vp);
        int error;

        if (cred->cr_uid != ip->i_uid) {
            error = priv_check_cred(cred, PRIV_VFS_CHMOD, 0);
            if (error)
                return (error);
        }
        if (cred->cr_uid) {
                if (vp->v_type != VDIR && (mode & S_ISTXT))
                        return (EFTYPE);
                if (!groupmember(ip->i_gid, cred) && (mode & ISGID))
                        return (EPERM);
        }
        ip->i_mode &= ~ALLPERMS;
        ip->i_mode |= (mode & ALLPERMS);
        ip->i_flag |= IN_CHANGE;
        return (0);
}

/*
 * Perform chown operation on inode ip;
 * inode must be locked prior to call.
 */
static int
ext2_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred)
{
        struct inode *ip = VTOI(vp);
        uid_t ouid;
        gid_t ogid;
        int error = 0;
#ifdef QUOTA
        int i;
        long change;
#endif

        if (uid == (uid_t)VNOVAL)
                uid = ip->i_uid;
        if (gid == (gid_t)VNOVAL)
                gid = ip->i_gid;
        /*
         * If we don't own the file, are trying to change the owner
         * of the file, or are not a member of the target group,
         * the caller must be superuser or the call fails.
         */
        if ((cred->cr_uid != ip->i_uid || uid != ip->i_uid ||
            (gid != ip->i_gid && !(cred->cr_gid == gid ||
            groupmember((gid_t)gid, cred)))) &&
            (error = priv_check_cred(cred, PRIV_VFS_CHOWN, 0)))
                return (error);
        ogid = ip->i_gid;
        ouid = ip->i_uid;
#ifdef QUOTA
        if ((error = ext2_getinoquota(ip)) != 0)
                return (error);
        if (ouid == uid) {
                ext2_dqrele(vp, ip->i_dquot[USRQUOTA]);
                ip->i_dquot[USRQUOTA] = NODQUOT;
        }
        if (ogid == gid) {
                ext2_dqrele(vp, ip->i_dquot[GRPQUOTA]);
                ip->i_dquot[GRPQUOTA] = NODQUOT;
        }
        change = ip->i_blocks;
        (void) ext2_chkdq(ip, -change, cred, CHOWN);
        (void) ext2_chkiq(ip, -1, cred, CHOWN);
        for (i = 0; i < MAXQUOTAS; i++) {
                ext2_dqrele(vp, ip->i_dquot[i]);
                ip->i_dquot[i] = NODQUOT;
        }
#endif
        ip->i_gid = gid;
        ip->i_uid = uid;
#ifdef QUOTA
        if ((error = ext2_getinoquota(ip)) == 0) {
                if (ouid == uid) {
                        ext2_dqrele(vp, ip->i_dquot[USRQUOTA]);
                        ip->i_dquot[USRQUOTA] = NODQUOT;
                }
                if (ogid == gid) {
                        ext2_dqrele(vp, ip->i_dquot[GRPQUOTA]);
                        ip->i_dquot[GRPQUOTA] = NODQUOT;
                }
                if ((error = ext2_chkdq(ip, change, cred, CHOWN)) == 0) {
                        if ((error = ext2_chkiq(ip, 1, cred, CHOWN)) == 0)
                                goto good;
                        else
                                (void)ext2_chkdq(ip, -change, cred, CHOWN|FORCE);
                }
                for (i = 0; i < MAXQUOTAS; i++) {
                        ext2_dqrele(vp, ip->i_dquot[i]);
                        ip->i_dquot[i] = NODQUOT;
                }
        }
        ip->i_gid = ogid;
        ip->i_uid = ouid;
        if (ext2_getinoquota(ip) == 0) {
                if (ouid == uid) {
                        ext2_dqrele(vp, ip->i_dquot[USRQUOTA]);
                        ip->i_dquot[USRQUOTA] = NODQUOT;
                }
                if (ogid == gid) {
                        ext2_dqrele(vp, ip->i_dquot[GRPQUOTA]);
                        ip->i_dquot[GRPQUOTA] = NODQUOT;
                }
                (void) ext2_chkdq(ip, change, cred, FORCE|CHOWN);
                (void) ext2_chkiq(ip, 1, cred, FORCE|CHOWN);
                (void) ext2_getinoquota(ip);
        }
        return (error);
good:
        if (ext2_getinoquota(ip))
                panic("ext2_chown: lost quota");
#endif /* QUOTA */
        ip->i_flag |= IN_CHANGE;
        if (cred->cr_uid != 0 && (ouid != uid || ogid != gid))
                ip->i_mode &= ~(ISUID | ISGID);
        return (0);
}

/*
 * Mmap a file
 *
 * NB Currently unsupported.
 *
 * ext2_mmap(struct vnode *a_vp, int a_fflags, struct ucred *a_cred)
 */
/* ARGSUSED */
static
int
ext2_mmap(struct vop_mmap_args *ap)
{
        return (EINVAL);
}

/*
 * whiteout vnode call
 *
 * ext2_whiteout(struct vnode *a_dvp, struct componentname *a_cnp, int a_flags)
 */
static
int
ext2_whiteout(struct vop_old_whiteout_args *ap)
{
        return (EOPNOTSUPP);
}

/*
 * Return target name of a symbolic link
 *
 * ext2_readlink(struct vnode *a_vp, struct uio *a_uio, struct ucred *a_cred)
 */
static
int
ext2_readlink(struct vop_readlink_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        int isize;

        isize = ip->i_size;
        if ((isize < vp->v_mount->mnt_maxsymlinklen) ||
            (ip->i_din.di_blocks == 0)) {   /* XXX - for old fastlink support */
                uiomove((char *)ip->i_shortlink, isize, ap->a_uio);
                return (0);
        }
        return (VOP_READ(vp, ap->a_uio, 0, ap->a_cred));
}

/*
 * Calculate the logical to physical mapping if not done already,
 * then call the device strategy routine.
 *
 * In order to be able to swap to a file, the VOP_BMAP operation may not
 * deadlock on memory.  See ext2_bmap() for details.
 *
 * ext2_strategy(struct vnode *a_vp, struct bio *a_bio)
 */
static
int
ext2_strategy(struct vop_strategy_args *ap)
{
        struct bio *bio = ap->a_bio;
        struct bio *nbio;
        struct buf *bp = bio->bio_buf;
        struct vnode *vp = ap->a_vp;
        struct inode *ip;
        int error;

        ip = VTOI(vp);
        if (vp->v_type == VBLK || vp->v_type == VCHR)
                panic("ext2_strategy: spec");
        nbio = push_bio(bio);
        if (nbio->bio_offset == NOOFFSET) {
                error = VOP_BMAP(vp, bio->bio_offset, &nbio->bio_offset,
                                 NULL, NULL, bp->b_cmd);
                if (error) {
                        bp->b_error = error;
                        bp->b_flags |= B_ERROR;
                        /* I/O was never started on nbio, must biodone(bio) */
                        biodone(bio);
                        return (error);
                }
                if (nbio->bio_offset == NOOFFSET)
                        vfs_bio_clrbuf(bp);
        }
        if (nbio->bio_offset == NOOFFSET) {
                /* I/O was never started on nbio, must biodone(bio) */
                biodone(bio);
                return (0);
        }
        vn_strategy(ip->i_devvp, nbio);
        return (0);
}

/*
 * Print out the contents of an inode.
 *
 * ext2_print(struct vnode *a_vp)
 */
static
int
ext2_print(struct vop_print_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);

        kprintf("tag VT_EXT2FS, ino %lu, on dev %s (%d, %d)",
            (u_long)ip->i_number, devtoname(ip->i_dev), major(ip->i_dev),
            minor(ip->i_dev));
        if (vp->v_type == VFIFO)
                fifo_printinfo(vp);
        lockmgr_printinfo(&vp->v_lock);
        kprintf("\n");
        return (0);
}

/*
 * Read wrapper for fifos.
 *
 * ext2fifo_read(struct vnode *a_vp, struct uio *a_uio, int a_ioflag,
 *              struct ucred *a_cred)
 */
static
int
ext2fifo_read(struct vop_read_args *ap)
{
        int error, resid;
        struct inode *ip;
        struct uio *uio;

        uio = ap->a_uio;
        resid = uio->uio_resid;
        error = VOCALL(&fifo_vnode_vops, &ap->a_head);
        ip = VTOI(ap->a_vp);
        if ((ap->a_vp->v_mount->mnt_flag & MNT_NOATIME) == 0 && ip != NULL &&
            (uio->uio_resid != resid || (error == 0 && resid != 0)))
                VTOI(ap->a_vp)->i_flag |= IN_ACCESS;
        return (error);
}

/*
 * Write wrapper for fifos.
 *
 * ext2fifo_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag,
 *               struct ucred *a_cred)
 */
static
int
ext2fifo_write(struct vop_write_args *ap)
{
        int error, resid;
        struct inode *ip;
        struct uio *uio;

        uio = ap->a_uio;
        resid = uio->uio_resid;
        error = VOCALL(&fifo_vnode_vops, &ap->a_head);
        ip = VTOI(ap->a_vp);
        if (ip != NULL && (uio->uio_resid != resid || (error == 0 && resid != 0)))
                VTOI(ap->a_vp)->i_flag |= IN_CHANGE | IN_UPDATE;
        return (error);
}

/*
 * Close wrapper for fifos.
 *
 * Update the times on the inode then do device close.
 *
 * ext2fifo_close(struct vnode *a_vp, int a_fflag, struct ucred *a_cred)
 */
static
int
ext2fifo_close(struct vop_close_args *ap)
{
        struct vnode *vp = ap->a_vp;

        if (vp->v_sysref.refcnt > 1)
                ext2_itimes(vp);
        return (VOCALL(&fifo_vnode_vops, &ap->a_head));
}

/*
 * Kqfilter wrapper for fifos.
 *
 * Fall through to ext2 kqfilter routines if needed 
 */
static
int
ext2fifo_kqfilter(struct vop_kqfilter_args *ap)
{
        int error;

        error = VOCALL(&fifo_vnode_vops, &ap->a_head);
        if (error)
                error = ext2_kqfilter(ap);
        return (error);
}

/*
 * Return POSIX pathconf information applicable to ext2 filesystems.
 *
 * ext2_pathconf(struct vnode *a_vp, int a_name, int *a_retval)
 */
static
int
ext2_pathconf(struct vop_pathconf_args *ap)
{
        switch (ap->a_name) {
        case _PC_LINK_MAX:
                *ap->a_retval = LINK_MAX;
                return (0);
        case _PC_NAME_MAX:
                *ap->a_retval = NAME_MAX;
                return (0);
        case _PC_PATH_MAX:
                *ap->a_retval = PATH_MAX;
                return (0);
        case _PC_PIPE_BUF:
                *ap->a_retval = PIPE_BUF;
                return (0);
        case _PC_CHOWN_RESTRICTED:
                *ap->a_retval = 1;
                return (0);
        case _PC_NO_TRUNC:
                *ap->a_retval = 1;
                return (0);
        default:
                return (EINVAL);
        }
        /* NOTREACHED */
}

/*
 * Advisory record locking support
 *
 * ext2_advlock(struct vnode *a_vp, caddr_t a_id, int a_op, struct flock *a_fl,
 *             int a_flags)
 */
static
int
ext2_advlock(struct vop_advlock_args *ap)
{
        struct inode *ip = VTOI(ap->a_vp);

        return (lf_advlock(ap, &(ip->i_lockf), ip->i_size));
}

/*
 * Initialize the vnode associated with a new inode, handle aliased
 * vnodes.
 */
int
ext2_vinit(struct mount *mntp, struct vnode **vpp)
{
        struct inode *ip;
        struct vnode *vp;
        struct timeval tv;

        vp = *vpp;
        ip = VTOI(vp);

        switch(vp->v_type = IFTOVT(ip->i_mode)) {
        case VCHR:
        case VBLK:
                vp->v_ops = &mntp->mnt_vn_spec_ops;
                addaliasu(vp, umajor(ip->i_rdev), uminor(ip->i_rdev));
                break;
        case VFIFO:
                vp->v_ops = &mntp->mnt_vn_fifo_ops;
                break;
        case VDIR:
        case VREG:
                vinitvmio(vp, ip->i_size);
                break;
        case VLNK:
                if ((ip->i_size >= vp->v_mount->mnt_maxsymlinklen) &&
                    ip->i_din.di_blocks != 0
                ) {
                        vinitvmio(vp, ip->i_size);
                }
                break;
        default:
                break;

        }

        if (ip->i_number == ROOTINO)
                vp->v_flag |= VROOT;
        /*
         * Initialize modrev times
         */
        getmicrouptime(&tv);
        SETHIGH(ip->i_modrev, tv.tv_sec);
        SETLOW(ip->i_modrev, tv.tv_usec * 4294);
        *vpp = vp;
        return (0);
}

static struct filterops ext2read_filtops = 
        { 1, NULL, filt_ext2detach, filt_ext2read };
static struct filterops ext2write_filtops = 
        { 1, NULL, filt_ext2detach, filt_ext2write };
static struct filterops ext2vnode_filtops = 
        { 1, NULL, filt_ext2detach, filt_ext2vnode };

/*
 * ext2_kqfilter(struct vnode *a_vp, struct knote *a_kn)
 */
static int
ext2_kqfilter(struct vop_kqfilter_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct knote *kn = ap->a_kn;
        lwkt_tokref vlock;

        switch (kn->kn_filter) {
        case EVFILT_READ:
                kn->kn_fop = &ext2read_filtops;
                break;
        case EVFILT_WRITE:
                kn->kn_fop = &ext2write_filtops;
                break;
        case EVFILT_VNODE:
                kn->kn_fop = &ext2vnode_filtops;
                break;
        default:
                return (1);
        }

        kn->kn_hook = (caddr_t)vp;

        lwkt_gettoken(&vlock, &vp->v_token);
        SLIST_INSERT_HEAD(&vp->v_pollinfo.vpi_selinfo.si_note, kn, kn_selnext);
        lwkt_reltoken(&vlock);

        return (0);
}

static void
filt_ext2detach(struct knote *kn)
{
        struct vnode *vp = (struct vnode *)kn->kn_hook;
        lwkt_tokref vlock;

        lwkt_gettoken(&vlock, &vp->v_token);
        SLIST_REMOVE(&vp->v_pollinfo.vpi_selinfo.si_note,
            kn, knote, kn_selnext);
        lwkt_reltoken(&vlock);
}

/*ARGSUSED*/
static int
filt_ext2read(struct knote *kn, long hint)
{
        struct vnode *vp = (struct vnode *)kn->kn_hook;
        struct inode *ip = VTOI(vp);

        /*
         * filesystem is gone, so set the EOF flag and schedule 
         * the knote for deletion.
         */
        if (hint == NOTE_REVOKE) {
                kn->kn_flags |= (EV_EOF | EV_ONESHOT);
                return (1);
        }

        kn->kn_data = ip->i_size - kn->kn_fp->f_offset;
        return (kn->kn_data != 0);
}

/*ARGSUSED*/
static int
filt_ext2write(struct knote *kn, long hint)
{
        /*
         * filesystem is gone, so set the EOF flag and schedule 
         * the knote for deletion.
         */
        if (hint == NOTE_REVOKE)
                kn->kn_flags |= (EV_EOF | EV_ONESHOT);

        kn->kn_data = 0;
        return (1);
}

static int
filt_ext2vnode(struct knote *kn, long hint)
{
        if (kn->kn_sfflags & hint)
                kn->kn_fflags |= hint;
        if (hint == NOTE_REVOKE) {
                kn->kn_flags |= EV_EOF;
                return (1);
        }
        return (kn->kn_fflags != 0);
}

struct vop_ops ext2_vnode_vops = {
        .vop_default =          vop_defaultop,
        .vop_fsync =            ext2_fsync,
        .vop_read =             ext2_read,
        .vop_reallocblks =      ext2_reallocblks,
        .vop_write =            ext2_write,
        .vop_access =           ext2_access,
        .vop_advlock =          ext2_advlock,
        .vop_bmap =             ext2_bmap,
        .vop_old_lookup =       ext2_lookup,
        .vop_close =            ext2_close,
        .vop_old_create =       ext2_create,
        .vop_getattr =          ext2_getattr,
        .vop_inactive =         ext2_inactive,
        .vop_old_link =         ext2_link,
        .vop_old_mkdir =        ext2_mkdir,
        .vop_old_mknod =        ext2_mknod,
        .vop_mmap =             ext2_mmap,
        .vop_open =             ext2_open,
        .vop_pathconf =         ext2_pathconf,
        .vop_poll =             vop_stdpoll,
        .vop_kqfilter =         ext2_kqfilter,
        .vop_print =            ext2_print,
        .vop_readdir =          ext2_readdir,
        .vop_readlink =         ext2_readlink,
        .vop_reclaim =          ext2_reclaim,
        .vop_old_remove =       ext2_remove,
        .vop_old_rename =       ext2_rename,
        .vop_old_rmdir =        ext2_rmdir,
        .vop_setattr =          ext2_setattr,
        .vop_strategy =         ext2_strategy,
        .vop_old_symlink =      ext2_symlink,
        .vop_old_whiteout =     ext2_whiteout,
        .vop_getpages =         vop_stdgetpages,
        .vop_putpages =         vop_stdputpages
};

struct vop_ops ext2_spec_vops = {
        .vop_default =          vop_defaultop,
        .vop_fsync =            ext2_fsync,
        .vop_access =           ext2_access,
        .vop_close =            ext2_close,
        .vop_getattr =          ext2_getattr,
        .vop_inactive =         ext2_inactive,
        .vop_print =            ext2_print,
        .vop_read =             vop_stdnoread,
        .vop_reclaim =          ext2_reclaim,
        .vop_setattr =          ext2_setattr,
        .vop_write =            vop_stdnowrite
};

struct vop_ops ext2_fifo_vops = {
        .vop_default =          ext2_vnoperatefifo,
        .vop_fsync =            ext2_fsync,
        .vop_access =           ext2_access,
        .vop_close =            ext2fifo_close,
        .vop_getattr =          ext2_getattr,
        .vop_inactive =         ext2_inactive,
        .vop_kqfilter =         ext2fifo_kqfilter,
        .vop_print =            ext2_print,
        .vop_read =             ext2fifo_read,
        .vop_reclaim =          ext2_reclaim,
        .vop_setattr =          ext2_setattr,
        .vop_write =            ext2fifo_write
};

VNODEOP_SET(ext2_vnode_vops);
VNODEOP_SET(ext2_spec_vops);
VNODEOP_SET(ext2_fifo_vops);

/*
 * ext2_vnoperate()
 */
int
ext2_vnoperate(struct vop_generic_args *ap)
{
        return (VOCALL(&ext2_vnode_vops, ap));
}

/*
 * ext2_vnoperatefifo()
 */
int
ext2_vnoperatefifo(struct vop_generic_args *ap)
{
        return (VOCALL(&ext2_fifo_vops, ap));
}