/*      $NetBSD: ext2fs_vnops.c,v 1.139 2024/01/29 18:27:09 christos Exp $      */

/*
 * 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. 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 8.14 (Berkeley) 10/26/94
 * Modified for ext2fs by Manuel Bouyer.
 */

/*
 * Copyright (c) 1997 Manuel Bouyer.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 8.14 (Berkeley) 10/26/94
 * Modified for ext2fs by Manuel Bouyer.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ext2fs_vnops.c,v 1.139 2024/01/29 18:27:09 christos Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/resourcevar.h>
#include <sys/kernel.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/lockf.h>
#include <sys/pool.h>
#include <sys/signalvar.h>
#include <sys/kauth.h>

#include <miscfs/fifofs/fifo.h>
#include <miscfs/genfs/genfs.h>
#include <miscfs/specfs/specdev.h>

#include <ufs/ufs/inode.h>
#include <ufs/ufs/ufs_extern.h>
#include <ufs/ufs/ufsmount.h>

#include <ufs/ext2fs/ext2fs.h>
#include <ufs/ext2fs/ext2fs_extern.h>
#include <ufs/ext2fs/ext2fs_dir.h>
#include <ufs/ext2fs/ext2fs_xattr.h>

extern int prtactive;

static int ext2fs_chmod(struct vnode *, int, kauth_cred_t, struct lwp *);
static int ext2fs_chown(struct vnode *, uid_t, gid_t, kauth_cred_t,
                                struct lwp *);
static int ext2fs_makeinode(struct vattr *, struct vnode *, struct vnode **,
                                struct componentname *, int);

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; \
}

/*
 * Create a regular file
 */
int
ext2fs_create(void *v)
{
        struct vop_create_v3_args /* {
                struct vnode *a_dvp;
                struct vnode **a_vpp;
                struct componentname *a_cnp;
                struct vattr *a_vap;
        } */ *ap = v;
        int     error;

        error = ext2fs_makeinode(ap->a_vap, ap->a_dvp, ap->a_vpp, ap->a_cnp, 1);

        if (error)
                return error;
        VOP_UNLOCK(*ap->a_vpp);
        return 0;
}

/*
 * Mknod vnode call
 */
/* ARGSUSED */
int
ext2fs_mknod(void *v)
{
        struct vop_mknod_v3_args /* {
                struct vnode *a_dvp;
                struct vnode **a_vpp;
                struct componentname *a_cnp;
                struct vattr *a_vap;
        } */ *ap = v;
        struct vattr *vap = ap->a_vap;
        struct vnode **vpp = ap->a_vpp;
        struct inode *ip;
        int error;

        if ((error = ext2fs_makeinode(vap, ap->a_dvp, vpp, ap->a_cnp, 1)) != 0)
                return error;
        ip = VTOI(*vpp);
        ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
        VOP_UNLOCK(*vpp);
        return 0;
}

/*
 * Open called.
 *
 * Just check the APPEND flag.
 */
/* ARGSUSED */
int
ext2fs_open(void *v)
{
        struct vop_open_args /* {
                struct vnode *a_vp;
                int  a_mode;
                kauth_cred_t a_cred;
        } */ *ap = v;

        /*
         * Files marked append-only must be opened for appending.
         */
        if ((VTOI(ap->a_vp)->i_e2fs_flags & EXT2_APPEND) &&
                (ap->a_mode & (FWRITE | O_APPEND)) == FWRITE)
                return EPERM;
        return 0;
}

static int
ext2fs_check_possible(struct vnode *vp, struct inode *ip, mode_t mode)
{

        /*
         * Disallow write attempts on read-only file systems;
         * unless the file is a socket, fifo, or a block or
         * character device resident on the file system.
         */
        if (mode & VWRITE) {
                switch (vp->v_type) {
                case VDIR:
                case VLNK:
                case VREG:
                        if (vp->v_mount->mnt_flag & MNT_RDONLY)
                                return EROFS;
                        break;
                default:
                        break;
                }
        }

        /* If immutable bit set, nobody gets to write it. */
        if ((mode & VWRITE) && (ip->i_e2fs_flags & EXT2_IMMUTABLE))
                return EPERM;

        return 0;
}

static int
ext2fs_check_permitted(struct vnode *vp, struct inode *ip, accmode_t accmode,
    kauth_cred_t cred)
{

        return kauth_authorize_vnode(cred, KAUTH_ACCESS_ACTION(accmode,
            vp->v_type, ip->i_e2fs_mode & ALLPERMS), vp, NULL,
            genfs_can_access(vp, cred, ip->i_uid, ip->i_gid,
            ip->i_e2fs_mode & ALLPERMS, NULL, accmode));
}

int
ext2fs_access(void *v)
{
        struct vop_access_args /* {
                struct vnode *a_vp;
                accmode_t  a_accmode;
                kauth_cred_t a_cred;
        } */ *ap = v;
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        accmode_t mode = ap->a_accmode;
        int error;

        error = ext2fs_check_possible(vp, ip, mode);
        if (error)
                return error;

        error = ext2fs_check_permitted(vp, ip, mode, ap->a_cred);

        return error;
}

/* ARGSUSED */
int
ext2fs_getattr(void *v)
{
        struct vop_getattr_args /* {
                struct vnode *a_vp;
                struct vattr *a_vap;
                kauth_cred_t a_cred;
        } */ *ap = v;
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        struct vattr *vap = ap->a_vap;

        EXT2FS_ITIMES(ip, NULL, NULL, NULL);
        /*
         * Copy from inode table
         */
        vap->va_fsid = ip->i_dev;
        vap->va_fileid = ip->i_number;
        vap->va_mode = ip->i_e2fs_mode & ALLPERMS;
        vap->va_nlink = ip->i_e2fs_nlink;
        vap->va_uid = ip->i_uid;
        vap->va_gid = ip->i_gid;
        vap->va_rdev = (dev_t)fs2h32(ip->i_din.e2fs_din->e2di_rdev);
        vap->va_size = vp->v_size;
        EXT2_DINODE_TIME_GET(&vap->va_atime, ip->i_din.e2fs_din, e2di_atime, EXT2_DINODE_SIZE(ip->i_e2fs));
        EXT2_DINODE_TIME_GET(&vap->va_mtime, ip->i_din.e2fs_din, e2di_mtime, EXT2_DINODE_SIZE(ip->i_e2fs));
        EXT2_DINODE_TIME_GET(&vap->va_ctime, ip->i_din.e2fs_din, e2di_ctime, EXT2_DINODE_SIZE(ip->i_e2fs));
        if (EXT2_DINODE_FITS(ip->i_din.e2fs_din, e2di_crtime, EXT2_DINODE_SIZE(ip->i_e2fs))) {
                EXT2_DINODE_TIME_GET(&vap->va_birthtime, ip->i_din.e2fs_din, e2di_crtime, EXT2_DINODE_SIZE(ip->i_e2fs));
        }

        vap->va_flags = 0;
        vap->va_flags |= (ip->i_e2fs_flags & EXT2_NODUMP) ? UF_NODUMP : 0;
        vap->va_flags |= (ip->i_e2fs_flags & EXT2_IMMUTABLE) ? SF_IMMUTABLE : 0;
        vap->va_flags |= (ip->i_e2fs_flags & EXT2_APPEND) ? SF_APPEND : 0;

        vap->va_gen = ip->i_e2fs_gen;
        /* this doesn't belong here */
        if (vp->v_type == VBLK)
                vap->va_blocksize = BLKDEV_IOSIZE;
        else if (vp->v_type == VCHR)
                vap->va_blocksize = MAXBSIZE;
        else
                vap->va_blocksize = vp->v_mount->mnt_stat.f_iosize;
        vap->va_bytes = dbtob(ext2fs_nblock(ip));
        vap->va_type = vp->v_type;
        vap->va_filerev = ip->i_modrev;
        return 0;
}

/*
 * Set attribute vnode op. called from several syscalls
 */
int
ext2fs_setattr(void *v)
{
        struct vop_setattr_args /* {
                struct vnode *a_vp;
                struct vattr *a_vap;
                kauth_cred_t a_cred;
        } */ *ap = v;
        struct vattr *vap = ap->a_vap;
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        kauth_cred_t cred = ap->a_cred;
        struct lwp *l = curlwp;
        int error;
        kauth_action_t action = KAUTH_VNODE_WRITE_FLAGS;
        bool changing_sysflags = false;

        /*
         * Check for unsettable attributes.
         */
        if ((vap->va_type != VNON) || (vap->va_nlink != (nlink_t)VNOVAL) ||
            (vap->va_fsid != VNOVAL) || (vap->va_fileid != VNOVAL) ||
            (vap->va_blocksize != VNOVAL) || (vap->va_rdev != 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;

                /* Indicate we're changing system flags if we are. */
                if ((vap->va_flags & SF_APPEND) ||
                     (vap->va_flags & SF_IMMUTABLE)) {
                        action |= KAUTH_VNODE_WRITE_SYSFLAGS;
                        changing_sysflags = true;
                }

                /* Indicate the node has system flags if it does. */
                if (ip->i_e2fs_flags & (EXT2_APPEND | EXT2_IMMUTABLE)) {
                        action |= KAUTH_VNODE_HAS_SYSFLAGS;
                }

                error = kauth_authorize_vnode(cred, action, vp, NULL,
                    genfs_can_chflags(vp, cred, ip->i_uid, changing_sysflags));
                if (error)
                        return error;

                ip->i_e2fs_flags &= ~(EXT2_APPEND | EXT2_IMMUTABLE | EXT2_NODUMP);
                ip->i_e2fs_flags |=
                    (vap->va_flags & SF_APPEND) ?  EXT2_APPEND : 0 |
                    (vap->va_flags & SF_IMMUTABLE) ? EXT2_IMMUTABLE : 0;
                ip->i_e2fs_flags |=
                    (vap->va_flags & UF_NODUMP) ? EXT2_NODUMP : 0;
                ip->i_flag |= IN_CHANGE;
                if (vap->va_flags & (IMMUTABLE | APPEND))
                        return 0;
        }
        if (ip->i_e2fs_flags & (EXT2_APPEND | EXT2_IMMUTABLE))
                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;
                error = ext2fs_chown(vp, vap->va_uid, vap->va_gid, cred, l);
                if (error)
                        return error;
        }
        if (vap->va_size != VNOVAL) {
                /*
                 * Disallow write attempts on read-only file systems;
                 * unless the file is a socket, fifo, or a block or
                 * character device resident on the file system.
                 */
                switch (vp->v_type) {
                case VDIR:
                        return EISDIR;
                case VLNK:
                case VREG:
                        if (vp->v_mount->mnt_flag & MNT_RDONLY)
                                return EROFS;
                default:
                        break;
                }
                error = ext2fs_truncate(vp, vap->va_size, 0, cred);
                if (error)
                        return error;
        }
        ip = VTOI(vp);
        if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL || vap->va_birthtime.tv_sec != VNOVAL) {
                if (vp->v_mount->mnt_flag & MNT_RDONLY)
                        return EROFS;
                error = kauth_authorize_vnode(cred, KAUTH_VNODE_WRITE_TIMES, vp,
                    NULL, genfs_can_chtimes(vp, cred, ip->i_uid,
                    vap->va_vaflags));
                if (error)
                        return error;
                if (vap->va_atime.tv_sec != VNOVAL)
                        if (!(vp->v_mount->mnt_flag & MNT_NOATIME))
                                ip->i_flag |= IN_ACCESS;
                if (vap->va_mtime.tv_sec != VNOVAL) {
                        ip->i_flag |= IN_CHANGE | IN_UPDATE;
                        if (vp->v_mount->mnt_flag & MNT_RELATIME)
                                ip->i_flag |= IN_ACCESS;
                }
                if (vap->va_birthtime.tv_sec != VNOVAL &&
                    EXT2_DINODE_FITS(ip->i_din.e2fs_din, e2di_crtime, EXT2_DINODE_SIZE(ip->i_e2fs))) {

                        EXT2_DINODE_TIME_SET(&vap->va_birthtime, ip->i_din.e2fs_din, e2di_crtime, EXT2_DINODE_SIZE(ip->i_e2fs));
                }
                error = ext2fs_update(vp, &vap->va_atime, &vap->va_mtime,
                        UPDATE_WAIT);
                if (error)
                        return error;
        }
        error = 0;
        if (vap->va_mode != (mode_t)VNOVAL) {
                if (vp->v_mount->mnt_flag & MNT_RDONLY)
                        return EROFS;
                error = ext2fs_chmod(vp, (int)vap->va_mode, cred, l);
        }
        return error;
}

/*
 * Change the mode on a file.
 * Inode must be locked before calling.
 */
static int
ext2fs_chmod(struct vnode *vp, int mode, kauth_cred_t cred, struct lwp *l)
{
        struct inode *ip = VTOI(vp);
        int error;

        error = kauth_authorize_vnode(cred, KAUTH_VNODE_WRITE_SECURITY, vp,
            NULL, genfs_can_chmod(vp, cred, ip->i_uid, ip->i_gid, mode));
        if (error)
                return error;

        ip->i_e2fs_mode &= ~ALLPERMS;
        ip->i_e2fs_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
ext2fs_chown(struct vnode *vp, uid_t uid, gid_t gid, kauth_cred_t cred,
                struct lwp *l)
{
        struct inode *ip = VTOI(vp);
        uid_t ouid;
        gid_t ogid;
        int error;

        if (uid == (uid_t)VNOVAL)
                uid = ip->i_uid;
        if (gid == (gid_t)VNOVAL)
                gid = ip->i_gid;

        error = kauth_authorize_vnode(cred, KAUTH_VNODE_CHANGE_OWNERSHIP, vp,
            NULL, genfs_can_chown(vp, cred, ip->i_uid, ip->i_gid, uid, gid));
        if (error)
                return error;

        ogid = ip->i_gid;
        ouid = ip->i_uid;

        ip->i_e2fs_gid = gid & 0xffff;
        ip->i_e2fs_uid = uid & 0xffff;
        if (ip->i_e2fs->e2fs.e2fs_rev > E2FS_REV0) {
                ip->i_e2fs_gid_high = (gid >> 16) & 0xffff;
                ip->i_e2fs_uid_high = (uid >> 16) & 0xffff;
        } else {
                ip->i_e2fs_gid_high = 0;
                ip->i_e2fs_uid_high = 0;
        }
        if (ouid != uid || ogid != gid) {
                ext2fs_set_inode_guid(ip);
                ip->i_flag |= IN_CHANGE;
        }
        if (ouid != uid && (ip->i_e2fs_mode & ISUID) &&
            kauth_authorize_vnode(cred, KAUTH_VNODE_RETAIN_SUID,
            vp, NULL, EPERM) != 0)
                ip->i_e2fs_mode &= ~ISUID;
        if (ogid != gid && (ip->i_e2fs_mode & ISGID) &&
            kauth_authorize_vnode(cred, KAUTH_VNODE_RETAIN_SGID,
            vp, NULL, EPERM) != 0)
                ip->i_e2fs_mode &= ~ISGID;
        return 0;
}

int
ext2fs_remove(void *v)
{
        struct vop_remove_v3_args /* {
                struct vnode *a_dvp;
                struct vnode *a_vp;
                struct componentname *a_cnp;
                nlink_t ctx_vp_new_nlink;
        } */ *ap = v;
        struct inode *ip;
        struct vnode *vp = ap->a_vp;
        struct vnode *dvp = ap->a_dvp;
        struct ufs_lookup_results *ulr;
        int error;

        /* XXX should handle this material another way */
        ulr = &VTOI(dvp)->i_crap;
        UFS_CHECK_CRAPCOUNTER(VTOI(dvp));

        ip = VTOI(vp);
        if (vp->v_type == VDIR ||
                (ip->i_e2fs_flags & (EXT2_IMMUTABLE | EXT2_APPEND)) ||
                (VTOI(dvp)->i_e2fs_flags & EXT2_APPEND)) {
                error = EPERM;
        } else {
                error = ext2fs_dirremove(dvp, ulr, ap->a_cnp);
                if (error == 0) {
                        ip->i_e2fs_nlink--;
                        ip->i_flag |= IN_CHANGE;
                        ap->ctx_vp_new_nlink = ip->i_e2fs_nlink;
                }
        }

        if (dvp == vp)
                vrele(vp);
        else
                vput(vp);
        return error;
}

/*
 * ext2fs_link: create hard link.
 */
int
ext2fs_link(void *v)
{
        struct vop_link_v2_args /* {
                struct vnode *a_dvp;
                struct vnode *a_vp;
                struct componentname *a_cnp;
        } */ *ap = v;
        struct vnode *dvp = ap->a_dvp;
        struct vnode *vp = ap->a_vp;
        struct componentname *cnp = ap->a_cnp;
        struct inode *ip;
        int error, abrt = 1;
        struct ufs_lookup_results *ulr;

        KASSERT(dvp != vp);
        KASSERT(vp->v_type != VDIR);
        KASSERT(dvp->v_mount == vp->v_mount);

        /* XXX should handle this material another way */
        ulr = &VTOI(dvp)->i_crap;
        UFS_CHECK_CRAPCOUNTER(VTOI(dvp));

        error = vn_lock(vp, LK_EXCLUSIVE);
        if (error)
                goto out2;
        error = kauth_authorize_vnode(cnp->cn_cred, KAUTH_VNODE_ADD_LINK, vp,
            dvp, 0);
        if (error)
                goto out1;
        ip = VTOI(vp);
        if ((nlink_t)ip->i_e2fs_nlink >= EXT2FS_LINK_MAX) {
                error = EMLINK;
                goto out1;
        }
        if (ip->i_e2fs_flags & (EXT2_IMMUTABLE | EXT2_APPEND)) {
                error = EPERM;
                goto out1;
        }
        ip->i_e2fs_nlink++;
        ip->i_flag |= IN_CHANGE;
        abrt = 0;
        error = ext2fs_update(vp, NULL, NULL, UPDATE_WAIT);
        if (!error)
                error = ext2fs_direnter(ip, dvp, ulr, cnp);
        if (error) {
                ip->i_e2fs_nlink--;
                ip->i_flag |= IN_CHANGE;
        }
out1:
        VOP_UNLOCK(vp);
out2:
        if (abrt)
                VOP_ABORTOP(dvp, cnp);
        return error;
}

/*
 * Mkdir system call
 */
int
ext2fs_mkdir(void *v)
{
        struct vop_mkdir_v3_args /* {
                struct vnode *a_dvp;
                struct vnode **a_vpp;
                struct componentname *a_cnp;
                struct vattr *a_vap;
        } */ *ap = v;
        struct vnode            *dvp = ap->a_dvp;
        struct componentname    *cnp = ap->a_cnp;
        struct inode            *ip, *dp = VTOI(dvp);
        struct vnode            *tvp;
        struct ext2fs_dirtemplate dirtemplate;
        int                     error;
        struct ufs_lookup_results *ulr;

        /* XXX should handle this material another way */
        ulr = &VTOI(dvp)->i_crap;
        UFS_CHECK_CRAPCOUNTER(VTOI(dvp));

        KASSERT(ap->a_vap->va_type == VDIR);

        /*
         * Acquire the inode, but don't sync/direnter it just yet
         */
        error = ext2fs_makeinode(ap->a_vap, ap->a_dvp, &tvp, ap->a_cnp, 0);
        if (error)
                goto out;

        /* the link count is going to be 2 when all is done */
        ip = VTOI(tvp);
        ip->i_e2fs_nlink = 2;

        /*
         * 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.
         */
        if (dp->i_e2fs_nlink != EXT2FS_LINK_INF)
                dp->i_e2fs_nlink++;

        /*
         * If we hit the link limit, for directories just set the nlink
         * to special value 1, which means the link count is bigger
         * than EXT2FS_LINK_MAX.
         */
        if ((nlink_t)dp->i_e2fs_nlink >= EXT2FS_LINK_MAX) {
                dp->i_e2fs_nlink = EXT2FS_LINK_INF;

                /* set the feature flag DIR_NLINK if not set already */
                if (!EXT2F_HAS_ROCOMPAT_FEATURE(dp->i_e2fs, EXT2F_ROCOMPAT_DIR_NLINK)) {
                        dp->i_e2fs->e2fs.e2fs_features_rocompat |= EXT2F_ROCOMPAT_DIR_NLINK;
                        dp->i_e2fs->e2fs_fmod = 1;
                }
        }

        dp->i_flag |= IN_CHANGE;
        if ((error = ext2fs_update(dvp, NULL, NULL, UPDATE_DIROP)) != 0)
                goto bad;

        /* Initialize directory with "." and ".." from static template. */
        memset(&dirtemplate, 0, sizeof(dirtemplate));
        dirtemplate.dot_ino = h2fs32(ip->i_number);
        dirtemplate.dot_reclen = h2fs16(12);
        dirtemplate.dot_namlen = 1;
        if (EXT2F_HAS_INCOMPAT_FEATURE(dp->i_e2fs, EXT2F_INCOMPAT_FTYPE)) {
                dirtemplate.dot_type = EXT2_FT_DIR;
        }
        dirtemplate.dot_name[0] = '.';
        dirtemplate.dotdot_ino = h2fs32(dp->i_number);
        dirtemplate.dotdot_reclen = h2fs16(VTOI(dvp)->i_e2fs->e2fs_bsize - 12);
        dirtemplate.dotdot_namlen = 2;
        if (EXT2F_HAS_INCOMPAT_FEATURE(dp->i_e2fs, EXT2F_INCOMPAT_FTYPE)) {
                dirtemplate.dotdot_type = EXT2_FT_DIR;
        }
        dirtemplate.dotdot_name[0] = dirtemplate.dotdot_name[1] = '.';
        error = ufs_bufio(UIO_WRITE, tvp, (void *)&dirtemplate,
            sizeof (dirtemplate), (off_t)0, IO_NODELOCKED|IO_SYNC,
            cnp->cn_cred, (size_t *)0, NULL);
        if (error) {
                if (dp->i_e2fs_nlink != EXT2FS_LINK_INF)
                        dp->i_e2fs_nlink--;
                dp->i_flag |= IN_CHANGE;
                goto bad;
        }
        if (VTOI(dvp)->i_e2fs->e2fs_bsize > dvp->v_mount->mnt_stat.f_bsize)
                panic("ext2fs_mkdir: blksize"); /* XXX should grow with balloc() */
        else {
                error = ext2fs_setsize(ip, VTOI(dvp)->i_e2fs->e2fs_bsize);
                if (error) {
                        if (dp->i_e2fs_nlink != EXT2FS_LINK_INF)
                                dp->i_e2fs_nlink--;
                        dp->i_flag |= IN_CHANGE;
                        goto bad;
                }
                ip->i_flag |= IN_CHANGE;
                uvm_vnp_setsize(tvp, ext2fs_size(ip));
        }

        /* Directory set up, now install its entry in the parent directory. */
        error = ext2fs_direnter(ip, dvp, ulr, cnp);
        if (error != 0) {
                if (dp->i_e2fs_nlink != EXT2FS_LINK_INF)
                        dp->i_e2fs_nlink--;
                dp->i_flag |= IN_CHANGE;
        }
bad:
        /*
         * No need to do an explicit ext2fs_truncate here, vrele will do this
         * for us because we set the link count to 0.
         */
        if (error) {
                ip->i_e2fs_nlink = 0;
                ip->i_flag |= IN_CHANGE;
                vput(tvp);
        } else {
                VOP_UNLOCK(tvp);
                *ap->a_vpp = tvp;
        }
out:
        return error;
}

/*
 * Rmdir system call.
 */
int
ext2fs_rmdir(void *v)
{
        struct vop_rmdir_v2_args /* {
                struct vnode *a_dvp;
                struct vnode *a_vp;
                struct componentname *a_cnp;
        } */ *ap = v;
        struct vnode *vp = ap->a_vp;
        struct vnode *dvp = ap->a_dvp;
        struct componentname *cnp = ap->a_cnp;
        struct inode *ip, *dp;
        int error;
        struct ufs_lookup_results *ulr;

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

        /* XXX should handle this material another way */
        ulr = &dp->i_crap;
        UFS_CHECK_CRAPCOUNTER(dp);

        /*
         * No rmdir "." please.
         */
        if (dp == ip) {
                vrele(vp);
                return EINVAL;
        }
        /*
         * 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_e2fs_nlink != 2 && ip->i_e2fs_nlink != EXT2FS_LINK_INF) ||
            !ext2fs_dirempty(ip, dp->i_number, cnp->cn_cred)) {
                error = ENOTEMPTY;
                goto out;
        }
        if ((dp->i_e2fs_flags & EXT2_APPEND) ||
                                 (ip->i_e2fs_flags & (EXT2_IMMUTABLE | EXT2_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 = ext2fs_dirremove(dvp, ulr, cnp);
        if (error != 0)
                goto out;
        if (dp->i_e2fs_nlink != EXT2FS_LINK_INF)
                dp->i_e2fs_nlink--;
        dp->i_flag |= IN_CHANGE;
        cache_purge(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_e2fs_nlink -= 2;
        error = ext2fs_truncate(vp, (off_t)0, IO_SYNC, cnp->cn_cred);
        cache_purge(ITOV(ip));
out:
        vput(vp);
        return error;
}

/*
 * symlink -- make a symbolic link
 */
int
ext2fs_symlink(void *v)
{
        struct vop_symlink_v3_args /* {
                struct vnode *a_dvp;
                struct vnode **a_vpp;
                struct componentname *a_cnp;
                struct vattr *a_vap;
                char *a_target;
        } */ *ap = v;
        struct vnode    *vp, **vpp;
        struct inode    *ip;
        int             len, error;

        vpp = ap->a_vpp;
        KASSERT(ap->a_vap->va_type == VLNK);
        error = ext2fs_makeinode(ap->a_vap, ap->a_dvp, vpp, ap->a_cnp, 1);
        if (error)
                return error;
        vp = *vpp;
        len = strlen(ap->a_target);
        ip = VTOI(vp);
        if (len < ip->i_ump->um_maxsymlinklen) {
                memcpy(ip->i_din.e2fs_din->e2di_shortlink, ap->a_target, len);
                error = ext2fs_setsize(ip, len);
                if (error)
                        goto bad;
                ip->i_flag |= IN_CHANGE | IN_UPDATE;
                if (vp->v_mount->mnt_flag & MNT_RELATIME)
                        ip->i_flag |= IN_ACCESS;
                uvm_vnp_setsize(vp, len);
        } else
                error = ufs_bufio(UIO_WRITE, vp, ap->a_target, len, (off_t)0,
                    IO_NODELOCKED, ap->a_cnp->cn_cred, (size_t *)0, NULL);
bad:
        VOP_UNLOCK(vp);
        if (error)
                vrele(vp);
        return error;
}

/*
 * Return target name of a symbolic link
 */
int
ext2fs_readlink(void *v)
{
        struct vop_readlink_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                kauth_cred_t a_cred;
        } */ *ap = v;
        struct vnode    *vp = ap->a_vp;
        struct inode    *ip = VTOI(vp);
        struct ufsmount *ump = ip->i_ump;
        int             isize;

        isize = ext2fs_size(ip);
        if (isize < ump->um_maxsymlinklen ||
            (ump->um_maxsymlinklen == 0 && ext2fs_nblock(ip) == 0)) {
                uiomove(ip->i_din.e2fs_din->e2di_shortlink, isize, ap->a_uio);
                return 0;
        }
        return UFS_BUFRD(vp, ap->a_uio, 0, ap->a_cred);
}

/*
 * Advisory record locking support
 */
int
ext2fs_advlock(void *v)
{
        struct vop_advlock_args /* {
                struct vnode *a_vp;
                void * a_id;
                int  a_op;
                struct flock *a_fl;
                int  a_flags;
        } */ *ap = v;
        struct inode *ip = VTOI(ap->a_vp);

        return lf_advlock(ap, &ip->i_lockf, ext2fs_size(ip));
}

int
ext2fs_fsync(void *v)
{
        struct vop_fsync_args /* {
                struct vnode *a_vp;
                kauth_cred_t a_cred;
                int a_flags;
                off_t offlo;
                off_t offhi;
                struct proc *a_p;
        } */ *ap = v;
        struct vnode *vp = ap->a_vp;
        int wait;
        int error;

        wait = (ap->a_flags & FSYNC_WAIT) != 0;

        if (vp->v_type == VBLK)
                error = spec_fsync(v);
        else
                error = vflushbuf(vp, ap->a_flags);
        if (error == 0 && (ap->a_flags & FSYNC_DATAONLY) == 0)
                error = ext2fs_update(vp, NULL, NULL, wait ? UPDATE_WAIT : 0);

        if (error == 0 && ap->a_flags & FSYNC_CACHE) {
                int l = 0;
                error = VOP_IOCTL(VTOI(vp)->i_devvp, DIOCCACHESYNC, &l, FWRITE,
                    curlwp->l_cred);
        }

        return error;
}

/*
 * Initialize the vnode associated with a new inode, handle aliased
 * vnodes.
 */
int
ext2fs_vinit(struct mount *mntp, int (**specops)(void *),
        int (**fifoops)(void *), struct vnode **vpp)
{
        struct timeval tv;
        struct inode *ip;
        struct vnode *vp;

        vp = *vpp;
        ip = VTOI(vp);
        switch(vp->v_type = IFTOVT(ip->i_e2fs_mode)) {
        case VCHR:
        case VBLK:
                vp->v_op = specops;
                spec_node_init(vp, fs2h32(ip->i_din.e2fs_din->e2di_rdev));
                break;
        case VFIFO:
                vp->v_op = fifoops;
                break;
        case VNON:
        case VBAD:
        case VSOCK:
        case VLNK:
        case VDIR:
        case VREG:
                break;
        }
        if (ip->i_number == UFS_ROOTINO)
                vp->v_vflag |= VV_ROOT;
        /*
         * Initialize modrev times
         */
        getmicrouptime(&tv);
        SETHIGH(ip->i_modrev, tv.tv_sec);
        SETLOW(ip->i_modrev, tv.tv_usec * 4294U);
        *vpp = vp;
        return 0;
}

/*
 * Allocate a new inode.
 */
static int
ext2fs_makeinode(struct vattr *vap, struct vnode *dvp, struct vnode **vpp,
                struct componentname *cnp, int do_direnter)
{
        struct inode *ip, *pdir;
        struct vnode *tvp;
        int error;
        struct ufs_lookup_results *ulr;

        pdir = VTOI(dvp);

        /* XXX should handle this material another way */
        ulr = &pdir->i_crap;
        UFS_CHECK_CRAPCOUNTER(pdir);

        *vpp = NULL;

        error = vcache_new(dvp->v_mount, dvp, vap, cnp->cn_cred, NULL, &tvp);
        if (error)
                return error;
        error = vn_lock(tvp, LK_EXCLUSIVE);
        if (error) {
                vrele(tvp);
                return error;
        }
        ip = VTOI(tvp);
        if (do_direnter) {
                /*
                 * Make sure inode goes to disk before directory entry.
                 */
                if ((error = ext2fs_update(tvp, NULL, NULL, UPDATE_WAIT)) != 0)
                        goto bad;
                error = ext2fs_direnter(ip, dvp, ulr, cnp);
                if (error != 0)
                        goto bad;
        }

        *vpp = tvp;
        cache_enter(dvp, *vpp, cnp->cn_nameptr, cnp->cn_namelen, cnp->cn_flags);
        return 0;

bad:
        /*
         * Write error occurred trying to update the inode
         * or the directory so must deallocate the inode.
         */
        ip->i_e2fs_nlink = 0;
        ip->i_flag |= IN_CHANGE;
        vput(tvp);
        return error;
}

/*
 * Reclaim an inode so that it can be used for other purposes.
 */
int
ext2fs_reclaim(void *v)
{
        struct vop_reclaim_v2_args /* {
                struct vnode *a_vp;
        } */ *ap = v;
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        int error;

        VOP_UNLOCK(vp);

        /*
         * The inode must be freed and updated before being removed
         * from its hash chain.  Other threads trying to gain a hold
         * or lock on the inode will be stalled.
         */
        if (ip->i_omode == 1 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0)
                ext2fs_vfree(vp, ip->i_number, ip->i_e2fs_mode);
        if ((error = ufs_reclaim(vp)) != 0)
                return error;
        if (ip->i_din.e2fs_din != NULL)
                kmem_free(ip->i_din.e2fs_din, EXT2_DINODE_SIZE(ip->i_e2fs));
        genfs_node_destroy(vp);
        pool_put(&ext2fs_inode_pool, vp->v_data);
        vp->v_data = NULL;
        return 0;
}

/* Global vfs data structures for ext2fs. */
int (**ext2fs_vnodeop_p)(void *);
const struct vnodeopv_entry_desc ext2fs_vnodeop_entries[] = {
        { &vop_default_desc, vn_default_error },
        { &vop_parsepath_desc, genfs_parsepath },       /* parsepath */
        { &vop_lookup_desc, ext2fs_lookup },            /* lookup */
        { &vop_create_desc, ext2fs_create },            /* create */
        { &vop_mknod_desc, ext2fs_mknod },              /* mknod */
        { &vop_open_desc, ext2fs_open },                /* open */
        { &vop_close_desc, ufs_close },                 /* close */
        { &vop_access_desc, ext2fs_access },            /* access */
        { &vop_accessx_desc, genfs_accessx },           /* accessx */
        { &vop_getattr_desc, ext2fs_getattr },          /* getattr */
        { &vop_setattr_desc, ext2fs_setattr },          /* setattr */
        { &vop_read_desc, ext2fs_read },                /* read */
        { &vop_write_desc, ext2fs_write },              /* write */
        { &vop_fallocate_desc, genfs_eopnotsupp },      /* fallocate */
        { &vop_fdiscard_desc, genfs_eopnotsupp },       /* fdiscard */
        { &vop_ioctl_desc, genfs_enoioctl },            /* ioctl */
        { &vop_fcntl_desc, genfs_fcntl },               /* fcntl */
        { &vop_poll_desc, genfs_poll },                 /* poll */
        { &vop_kqfilter_desc, genfs_kqfilter },         /* kqfilter */
        { &vop_revoke_desc, genfs_revoke },             /* revoke */
        { &vop_mmap_desc, genfs_mmap },                 /* mmap */
        { &vop_fsync_desc, ext2fs_fsync },              /* fsync */
        { &vop_seek_desc, genfs_seek },                 /* seek */
        { &vop_remove_desc, ext2fs_remove },            /* remove */
        { &vop_link_desc, ext2fs_link },                /* link */
        { &vop_rename_desc, ext2fs_rename },            /* rename */
        { &vop_mkdir_desc, ext2fs_mkdir },              /* mkdir */
        { &vop_rmdir_desc, ext2fs_rmdir },              /* rmdir */
        { &vop_symlink_desc, ext2fs_symlink },          /* symlink */
        { &vop_readdir_desc, ext2fs_readdir },          /* readdir */
        { &vop_readlink_desc, ext2fs_readlink },        /* readlink */
        { &vop_abortop_desc, genfs_abortop },           /* abortop */
        { &vop_inactive_desc, ext2fs_inactive },        /* inactive */
        { &vop_reclaim_desc, ext2fs_reclaim },          /* reclaim */
        { &vop_lock_desc, genfs_lock },                 /* lock */
        { &vop_unlock_desc, genfs_unlock },             /* unlock */
        { &vop_bmap_desc, ext2fs_bmap },                /* bmap */
        { &vop_strategy_desc, ufs_strategy },           /* strategy */
        { &vop_print_desc, ufs_print },                 /* print */
        { &vop_islocked_desc, genfs_islocked },         /* islocked */
        { &vop_pathconf_desc, ufs_pathconf },           /* pathconf */
        { &vop_advlock_desc, ext2fs_advlock },          /* advlock */
        { &vop_bwrite_desc, vn_bwrite },                /* bwrite */
        { &vop_getpages_desc, genfs_getpages },         /* getpages */
        { &vop_putpages_desc, genfs_putpages },         /* putpages */
        { &vop_getextattr_desc, ext2fs_getextattr },    /* getextattr */
        { &vop_setextattr_desc, ext2fs_setextattr },    /* setextattr */
        { &vop_listextattr_desc, ext2fs_listextattr },  /* listextattr */
        { &vop_deleteextattr_desc, ext2fs_deleteextattr },/* deleteextattr */
        { NULL, NULL }
};
const struct vnodeopv_desc ext2fs_vnodeop_opv_desc =
        { &ext2fs_vnodeop_p, ext2fs_vnodeop_entries };

int (**ext2fs_specop_p)(void *);
const struct vnodeopv_entry_desc ext2fs_specop_entries[] = {
        { &vop_default_desc, vn_default_error },
        GENFS_SPECOP_ENTRIES,
        { &vop_close_desc, ufsspec_close },             /* close */
        { &vop_access_desc, ext2fs_access },            /* access */
        { &vop_accessx_desc, genfs_accessx },           /* accessx */
        { &vop_getattr_desc, ext2fs_getattr },          /* getattr */
        { &vop_setattr_desc, ext2fs_setattr },          /* setattr */
        { &vop_read_desc, ufsspec_read },               /* read */
        { &vop_write_desc, ufsspec_write },             /* write */
        { &vop_fcntl_desc, genfs_fcntl },               /* fcntl */
        { &vop_fsync_desc, ext2fs_fsync },              /* fsync */
        { &vop_inactive_desc, ext2fs_inactive },        /* inactive */
        { &vop_reclaim_desc, ext2fs_reclaim },          /* reclaim */
        { &vop_lock_desc, genfs_lock },                 /* lock */
        { &vop_unlock_desc, genfs_unlock },             /* unlock */
        { &vop_print_desc, ufs_print },                 /* print */
        { &vop_islocked_desc, genfs_islocked },         /* islocked */
        { &vop_bwrite_desc, vn_bwrite },                /* bwrite */
        { &vop_getextattr_desc, ext2fs_getextattr },    /* getextattr */
        { &vop_setextattr_desc, ext2fs_setextattr },    /* setextattr */
        { &vop_listextattr_desc, ext2fs_listextattr },  /* listextattr */
        { &vop_deleteextattr_desc, ext2fs_deleteextattr },/* deleteextattr */
        { NULL, NULL }
};
const struct vnodeopv_desc ext2fs_specop_opv_desc =
        { &ext2fs_specop_p, ext2fs_specop_entries };

int (**ext2fs_fifoop_p)(void *);
const struct vnodeopv_entry_desc ext2fs_fifoop_entries[] = {
        { &vop_default_desc, vn_default_error },
        GENFS_FIFOOP_ENTRIES,
        { &vop_close_desc, ufsfifo_close },             /* close */
        { &vop_access_desc, ext2fs_access },            /* access */
        { &vop_accessx_desc, genfs_accessx },           /* accessx */
        { &vop_getattr_desc, ext2fs_getattr },          /* getattr */
        { &vop_setattr_desc, ext2fs_setattr },          /* setattr */
        { &vop_read_desc, ufsfifo_read },               /* read */
        { &vop_write_desc, ufsfifo_write },             /* write */
        { &vop_fcntl_desc, genfs_fcntl },               /* fcntl */
        { &vop_fsync_desc, ext2fs_fsync },              /* fsync */
        { &vop_inactive_desc, ext2fs_inactive },        /* inactive */
        { &vop_reclaim_desc, ext2fs_reclaim },          /* reclaim */
        { &vop_lock_desc, genfs_lock },                 /* lock */
        { &vop_unlock_desc, genfs_unlock },             /* unlock */
        { &vop_strategy_desc, vn_fifo_bypass },         /* strategy */
        { &vop_print_desc, ufs_print },                 /* print */
        { &vop_islocked_desc, genfs_islocked },         /* islocked */
        { &vop_bwrite_desc, vn_bwrite },                /* bwrite */
        { &vop_getextattr_desc, ext2fs_getextattr },    /* getextattr */
        { &vop_setextattr_desc, ext2fs_setextattr },    /* setextattr */
        { &vop_listextattr_desc, ext2fs_listextattr },  /* listextattr */
        { &vop_deleteextattr_desc, ext2fs_deleteextattr },/* deleteextattr */
        { NULL, NULL }
};
const struct vnodeopv_desc ext2fs_fifoop_opv_desc =
        { &ext2fs_fifoop_p, ext2fs_fifoop_entries };