/*      $OpenBSD: ext2fs_vnops.c,v 1.95 2025/06/01 00:32:54 rsadowski Exp $     */
/*      $NetBSD: ext2fs_vnops.c,v 1.1 1997/06/11 09:34:09 bouyer Exp $  */

/*
 * Copyright (c) 1997 Manuel Bouyer.
 * 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.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/resourcevar.h>
#include <sys/kernel.h>
#include <sys/fcntl.h>
#include <sys/stat.h>
#include <sys/proc.h>
#include <sys/conf.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/lockf.h>
#include <sys/malloc.h>
#include <sys/pool.h>
#include <sys/signalvar.h>
#include <sys/specdev.h>
#include <sys/unistd.h>

#include <miscfs/fifofs/fifo.h>

#include <ufs/ufs/quota.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 <uvm/uvm_extern.h>

static int ext2fs_chmod(struct vnode *, mode_t, struct ucred *);
static int ext2fs_chown(struct vnode *, uid_t, gid_t, struct ucred *);

/*
 * Create a regular file
 */
int
ext2fs_create(void *v)
{
        struct vop_create_args *ap = v;

        return (ext2fs_makeinode(MAKEIMODE(ap->a_vap->va_type,
            ap->a_vap->va_mode), ap->a_dvp, ap->a_vpp, ap->a_cnp));
}

/*
 * Mknod vnode call
 */
int
ext2fs_mknod(void *v)
{
        struct vop_mknod_args *ap = v;
        struct vattr *vap = ap->a_vap;
        struct vnode **vpp = ap->a_vpp;
        struct inode *ip;
        int error;

        error = ext2fs_makeinode(MAKEIMODE(vap->va_type, vap->va_mode),
            ap->a_dvp, vpp, ap->a_cnp);
        if (error != 0)
                return (error);
        ip = VTOI(*vpp);
        ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
        if (vap->va_rdev != VNOVAL) {
                /*
                 * Want to be able to use this to make badblock
                 * inodes, so don't truncate the dev number.
                 */
                ip->i_e2din->e2di_rdev = htole32(vap->va_rdev);
        }
        /*
         * Remove inode so that it will be reloaded by VFS_VGET and
         * checked to see if it is an alias of an existing entry in
         * the inode cache.
         */
        vput(*vpp);
        (*vpp)->v_type = VNON;
        vgone(*vpp);
        *vpp = NULL;
        return (0);
}

/*
 * Open called.
 *
 * Just check the APPEND flag.
 */
int
ext2fs_open(void *v)
{
        struct vop_open_args *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);
}

int
ext2fs_access(void *v)
{
        struct vop_access_args *ap = v;
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        mode_t mode = ap->a_mode;

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

        return (vaccess(vp->v_type, ip->i_e2fs_mode, ip->i_e2fs_uid,
                        ip->i_e2fs_gid, mode, ap->a_cred));
}

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

        EXT2FS_ITIMES(ip);
        /*
         * 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_e2fs_uid;
        vap->va_gid = ip->i_e2fs_gid;
        vap->va_rdev = (dev_t) letoh32(ip->i_e2din->e2di_rdev);
        vap->va_size = ext2fs_size(ip);
        vap->va_atime.tv_sec = ip->i_e2fs_atime;
        vap->va_atime.tv_nsec = 0;
        vap->va_mtime.tv_sec = ip->i_e2fs_mtime;
        vap->va_mtime.tv_nsec = 0;
        vap->va_ctime.tv_sec = ip->i_e2fs_ctime;
        vap->va_ctime.tv_nsec = 0;
        vap->va_flags = (ip->i_e2fs_flags & EXT2_APPEND) ? SF_APPEND : 0;
        vap->va_flags |= (ip->i_e2fs_flags & EXT2_IMMUTABLE) ? SF_IMMUTABLE : 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((u_quad_t)ip->i_e2fs_nblock);
        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 *ap = v;
        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_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);
                if (cred->cr_uid != ip->i_e2fs_uid &&
                        (error = suser_ucred(cred)))
                        return (error);
                if (cred->cr_uid == 0) {
                        if ((ip->i_e2fs_flags &
                            (EXT2_APPEND | EXT2_IMMUTABLE)) && securelevel > 0)
                                return (EPERM);
                        ip->i_e2fs_flags &= ~(EXT2_APPEND | EXT2_IMMUTABLE);
                        ip->i_e2fs_flags |=
                            (vap->va_flags & SF_APPEND) ? EXT2_APPEND : 0 |
                            (vap->va_flags & SF_IMMUTABLE) ? EXT2_IMMUTABLE: 0;
                } else {
                        return (EPERM);
                }
                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);
                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(ip, vap->va_size, 0, cred);
                if (error)
                        return (error);
        }
        if ((vap->va_vaflags & VA_UTIMES_CHANGE) ||
            vap->va_atime.tv_nsec != VNOVAL ||
            vap->va_mtime.tv_nsec != VNOVAL) {
                if (vp->v_mount->mnt_flag & MNT_RDONLY)
                        return (EROFS);
                if (cred->cr_uid != ip->i_e2fs_uid &&
                        (error = suser_ucred(cred)) &&
                        ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
                        (error = VOP_ACCESS(vp, VWRITE, cred, ap->a_p))))
                        return (error);
                if (vap->va_mtime.tv_nsec != VNOVAL)
                        ip->i_flag |= IN_CHANGE | IN_UPDATE;
                else if (vap->va_vaflags & VA_UTIMES_CHANGE)
                        ip->i_flag |= IN_CHANGE;
                if (vap->va_atime.tv_nsec != VNOVAL) {
                        if (!(vp->v_mount->mnt_flag & MNT_NOATIME) ||
                            (ip->i_flag & (IN_CHANGE | IN_UPDATE)))
                                ip->i_flag |= IN_ACCESS;
                }
                EXT2FS_ITIMES(ip);
                if (vap->va_mtime.tv_nsec != VNOVAL)
                        ip->i_e2fs_mtime = vap->va_mtime.tv_sec;
                if (vap->va_atime.tv_nsec != VNOVAL)
                        ip->i_e2fs_atime = vap->va_atime.tv_sec;
                error = ext2fs_update(ip, 1);
                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, vap->va_mode, cred);
        }
        return (error);
}

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

        if (cred->cr_uid != ip->i_e2fs_uid && (error = suser_ucred(cred)))
                return (error);
        if (cred->cr_uid) {
                if (vp->v_type != VDIR && (mode & S_ISTXT))
                        return (EFTYPE);
                if (!groupmember(ip->i_e2fs_gid, cred) && (mode & ISGID))
                        return (EPERM);
        }
        ip->i_e2fs_mode &= ~ALLPERMS;
        ip->i_e2fs_mode |= (mode & ALLPERMS);
        ip->i_flag |= IN_CHANGE;
        if ((vp->v_flag & VTEXT) && (ip->i_e2fs_mode & S_ISTXT) == 0)
                (void) uvm_vnp_uncache(vp);
        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, struct ucred *cred)
{
        struct inode *ip = VTOI(vp);
        uid_t ouid;
        gid_t ogid;
        int error = 0;

        if (uid == (uid_t)VNOVAL)
                uid = ip->i_e2fs_uid;
        if (gid == (gid_t)VNOVAL)
                gid = ip->i_e2fs_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_e2fs_uid || uid != ip->i_e2fs_uid ||
                (gid != ip->i_e2fs_gid && !groupmember(gid, cred))) &&
                (error = suser_ucred(cred)))
                return (error);
        ogid = ip->i_e2fs_gid;
        ouid = ip->i_e2fs_uid;

        ip->i_e2fs_gid = gid;
        ip->i_e2fs_uid = uid;
        if (ouid != uid || ogid != gid)
                ip->i_flag |= IN_CHANGE;
        if (ouid != uid && cred->cr_uid != 0)
                ip->i_e2fs_mode &= ~ISUID;
        if (ogid != gid && cred->cr_uid != 0)
                ip->i_e2fs_mode &= ~ISGID;
        return (0);
}

int
ext2fs_remove(void *v)
{
        struct vop_remove_args *ap = v;
        struct inode *ip;
        struct vnode *vp = ap->a_vp;
        struct vnode *dvp = ap->a_dvp;
        int error;

        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;
                goto out;
        }
        error = ext2fs_dirremove(dvp, ap->a_cnp);
        if (error == 0) {
                ip->i_e2fs_nlink--;
                ip->i_flag |= IN_CHANGE;
        }
out:
        return (error);
}

/*
 * link vnode call
 */
int
ext2fs_link(void *v)
{
        struct vop_link_args *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;

#ifdef DIAGNOSTIC
        if ((cnp->cn_flags & HASBUF) == 0)
                panic("ext2fs_link: no name");
#endif
        if (dvp != vp && (error = vn_lock(vp, LK_EXCLUSIVE))) {
                VOP_ABORTOP(dvp, cnp);
                goto out2;
        }
        ip = VTOI(vp);
        if ((nlink_t)ip->i_e2fs_nlink >= LINK_MAX) {
                VOP_ABORTOP(dvp, cnp);
                error = EMLINK;
                goto out1;
        }
        if (ip->i_e2fs_flags & (EXT2_IMMUTABLE | EXT2_APPEND)) {
                VOP_ABORTOP(dvp, cnp);
                error = EPERM;
                goto out1;
        }
        ip->i_e2fs_nlink++;
        ip->i_flag |= IN_CHANGE;
        error = ext2fs_update(ip, 1);
        if (!error)
                error = ext2fs_direnter(ip, dvp, cnp);
        if (error) {
                ip->i_e2fs_nlink--;
                ip->i_flag |= IN_CHANGE;
        }
        pool_put(&namei_pool, cnp->cn_pnbuf);
out1:
        if (dvp != vp)
                VOP_UNLOCK(vp);
out2:
        vput(dvp);
        return (error);
}

/*
 * Rename system call.
 *      rename("foo", "bar");
 * is essentially
 *      unlink("bar");
 *      link("foo", "bar");
 *      unlink("foo");
 * but ``atomically''.  Can't do full commit without saving state in the
 * inode on disk which isn't feasible at this time.  Best we can do is
 * always guarantee the target exists.
 *
 * Basic algorithm is:
 *
 * 1) Bump link count on source while we're linking it to the
 *    target.  This also ensure the inode won't be deleted out
 *    from underneath us while we work (it may be truncated by
 *    a concurrent `trunc' or `open' for creation).
 * 2) Link source to destination.  If destination already exists,
 *    delete it first.
 * 3) Unlink source reference to inode if still around. If a
 *    directory was moved and the parent of the destination
 *    is different from the source, patch the ".." entry in the
 *    directory.
 */
int
ext2fs_rename(void *v)
{
        struct vop_rename_args  *ap = v;
        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 ext2fs_dirtemplate dirbuf;
        /* struct timespec ts; */
        int doingdirectory = 0, oldparent = 0, newparent = 0;
        int error = 0;
        u_char namlen;

#ifdef DIAGNOSTIC
        if ((tcnp->cn_flags & HASBUF) == 0 ||
            (fcnp->cn_flags & HASBUF) == 0)
                panic("ext2fs_rename: no name");
#endif
        /*
         * Check for cross-device rename.
         */
        if ((fvp->v_mount != tdvp->v_mount) ||
            (tvp && (fvp->v_mount != tvp->v_mount))) {
                error = EXDEV;
abortit:
                VOP_ABORTOP(tdvp, tcnp); /* XXX, why not in NFS? */
                if (tdvp == tvp)
                        vrele(tdvp);
                else
                        vput(tdvp);
                if (tvp)
                        vput(tvp);
                VOP_ABORTOP(fdvp, fcnp); /* XXX, why not in NFS? */
                vrele(fdvp);
                vrele(fvp);
                return (error);
        }

        /*
         * Check if just deleting a link name.
         */
        if (tvp && ((VTOI(tvp)->i_e2fs_flags & (EXT2_IMMUTABLE | EXT2_APPEND)) ||
            (VTOI(tdvp)->i_e2fs_flags & EXT2_APPEND))) {
                error = EPERM;
                goto abortit;
        }
        if (fvp == tvp) {
                if (fvp->v_type == VDIR) {
                        error = EINVAL;
                        goto abortit;
                }

                /* Release destination completely. */
                VOP_ABORTOP(tdvp, tcnp);
                vput(tdvp);
                vput(tvp);

                /* Delete source. */
                vrele(fdvp);
                vrele(fvp);
                fcnp->cn_flags &= ~MODMASK;
                fcnp->cn_flags |= LOCKPARENT | LOCKLEAF;
                if ((fcnp->cn_flags & SAVESTART) == 0)
                        panic("ext2fs_rename: lost from startdir");
                fcnp->cn_nameiop = DELETE;
                (void) vfs_relookup(fdvp, &fvp, fcnp);
                return (VOP_REMOVE(fdvp, fvp, fcnp));
        }
        if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0)
                goto abortit;
        dp = VTOI(fdvp);
        ip = VTOI(fvp);
        if ((nlink_t)ip->i_e2fs_nlink >= LINK_MAX) {
                VOP_UNLOCK(fvp);
                error = EMLINK;
                goto abortit;
        }
        if ((ip->i_e2fs_flags & (EXT2_IMMUTABLE | EXT2_APPEND)) ||
                (dp->i_e2fs_flags & EXT2_APPEND)) {
                VOP_UNLOCK(fvp);
                error = EPERM;
                goto abortit;
        }
        if ((ip->i_e2fs_mode & IFMT) == IFDIR) {
                error = VOP_ACCESS(fvp, VWRITE, tcnp->cn_cred, tcnp->cn_proc);
                if (!error && tvp)
                        error = VOP_ACCESS(tvp, VWRITE, tcnp->cn_cred,
                            tcnp->cn_proc);
                if (error) {
                        VOP_UNLOCK(fvp);
                        error = EACCES;
                        goto abortit;
                }
                /*
                 * Avoid ".", "..", and aliases of "." for obvious reasons.
                 */
                if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.') ||
                    dp == ip ||
                        (fcnp->cn_flags&ISDOTDOT) ||
                        (tcnp->cn_flags & ISDOTDOT) ||
                    (ip->i_flag & IN_RENAME)) {
                        VOP_UNLOCK(fvp);
                        error = EINVAL;
                        goto abortit;
                }
                ip->i_flag |= IN_RENAME;
                oldparent = dp->i_number;
                doingdirectory++;
        }
        vrele(fdvp);

        /*
         * When the target exists, both the directory
         * and target vnodes are returned locked.
         */
        dp = VTOI(tdvp);
        xp = NULL;
        if (tvp)
                xp = VTOI(tvp);

        /*
         * 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_e2fs_nlink++;
        ip->i_flag |= IN_CHANGE;
        if ((error = ext2fs_update(ip, 1)) != 0) {
                VOP_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 hierarchy 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_ACCESS(fvp, VWRITE, tcnp->cn_cred, tcnp->cn_proc);
        VOP_UNLOCK(fvp);
        if (oldparent != dp->i_number)
                newparent = dp->i_number;
        if (doingdirectory && newparent) {
                if (error)      /* write access check above */
                        goto bad;
                if (xp != NULL)
                        vput(tvp);
                error = ext2fs_checkpath(ip, dp, tcnp->cn_cred);
                if (error != 0)
                        goto out;
                if ((tcnp->cn_flags & SAVESTART) == 0)
                        panic("ext2fs_rename: lost to startdir");
                if ((error = vfs_relookup(tdvp, &tvp, tcnp)) != 0)
                        goto out;
                dp = VTOI(tdvp);
                xp = NULL;
                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.
         */
        if (xp == NULL) {
                if (dp->i_dev != ip->i_dev)
                        panic("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_e2fs_nlink >= LINK_MAX) {
                                error = EMLINK;
                                goto bad;
                        }
                        dp->i_e2fs_nlink++;
                        dp->i_flag |= IN_CHANGE;
                        if ((error = ext2fs_update(dp, 1)) != 0)
                                goto bad;
                }
                error = ext2fs_direnter(ip, tdvp, tcnp);
                if (error != 0) {
                        if (doingdirectory && newparent) {
                                dp->i_e2fs_nlink--;
                                dp->i_flag |= IN_CHANGE;
                                (void)ext2fs_update(dp, 1);
                        }
                        goto bad;
                }
                vput(tdvp);
        } else {
                if (xp->i_dev != dp->i_dev || xp->i_dev != ip->i_dev)
                        panic("rename: EXDEV");
                /*
                 * Short circuit rename(foo, foo).
                 */
                if (xp->i_number == ip->i_number)
                        panic("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_e2fs_mode & S_ISTXT) && tcnp->cn_cred->cr_uid != 0 &&
                    tcnp->cn_cred->cr_uid != dp->i_e2fs_uid &&
                    xp->i_e2fs_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_e2fs_mode & IFMT) == IFDIR) {
                        if (!ext2fs_dirempty(xp, dp->i_number, tcnp->cn_cred) ||
                                xp->i_e2fs_nlink > 2) {
                                error = ENOTEMPTY;
                                goto bad;
                        }
                        if (!doingdirectory) {
                                error = ENOTDIR;
                                goto bad;
                        }
                        cache_purge(tdvp);
                } else if (doingdirectory) {
                        error = EISDIR;
                        goto bad;
                }
                error = ext2fs_dirrewrite(dp, ip, tcnp);
                if (error != 0)
                        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_e2fs_nlink--;
                        dp->i_flag |= IN_CHANGE;
                }
                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_e2fs_nlink--;
                if (doingdirectory) {
                        if (--xp->i_e2fs_nlink != 0)
                                panic("rename: linked directory");
                        error = ext2fs_truncate(xp, (off_t)0, IO_SYNC,
                            tcnp->cn_cred);
                }
                xp->i_flag |= IN_CHANGE;
                vput(tvp);
                xp = NULL;
        }

        /*
         * 3) Unlink the source.
         */
        fcnp->cn_flags &= ~MODMASK;
        fcnp->cn_flags |= LOCKPARENT | LOCKLEAF;
        if ((fcnp->cn_flags & SAVESTART) == 0)
                panic("ext2fs_rename: lost from startdir");
        (void) vfs_relookup(fdvp, &fvp, fcnp);
        if (fvp != NULL) {
                xp = VTOI(fvp);
                dp = VTOI(fdvp);
        } else {
                /*
                 * From name has disappeared.
                 */
                if (doingdirectory)
                        panic("ext2fs_rename: lost dir entry");
                vrele(ap->a_fvp);
                return (0);
        }
        /*
         * 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 IRENAME flag ensures that it cannot be moved by another
         * rename.
         */
        if (xp != ip) {
                if (doingdirectory)
                        panic("ext2fs_rename: lost dir entry");
        } 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_e2fs_nlink--;
                        dp->i_flag |= IN_CHANGE;
                        error = vn_rdwr(UIO_READ, fvp, (caddr_t)&dirbuf,
                                sizeof (struct ext2fs_dirtemplate), (off_t)0,
                                UIO_SYSSPACE, IO_NODELOCKED,
                                tcnp->cn_cred, NULL, curproc);
                        if (error == 0) {
                                namlen = dirbuf.dotdot_namlen;
                                if (namlen != 2 ||
                                    dirbuf.dotdot_name[0] != '.' ||
                                    dirbuf.dotdot_name[1] != '.') {
                                        ufs_dirbad(xp, (doff_t)12,
                                            "ext2fs_rename: mangled dir");
                                } else {
                                        dirbuf.dotdot_ino = htole32(newparent);
                                        (void) vn_rdwr(UIO_WRITE, fvp,
                                            (caddr_t)&dirbuf,
                                            sizeof (struct dirtemplate),
                                            (off_t)0, UIO_SYSSPACE,
                                            IO_NODELOCKED|IO_SYNC,
                                            tcnp->cn_cred, NULL, curproc);
                                        cache_purge(fdvp);
                                }
                        }
                }
                error = ext2fs_dirremove(fdvp, fcnp);
                if (!error) {
                        xp->i_e2fs_nlink--;
                        xp->i_flag |= IN_CHANGE;
                }
                xp->i_flag &= ~IN_RENAME;
        }
        if (dp)
                vput(fdvp);
        if (xp)
                vput(fvp);
        vrele(ap->a_fvp);
        return (error);

bad:
        if (xp)
                vput(ITOV(xp));
        vput(ITOV(dp));
out:
        if (doingdirectory)
                ip->i_flag &= ~IN_RENAME;
        if (vn_lock(fvp, LK_EXCLUSIVE) == 0) {
                ip->i_e2fs_nlink--;
                ip->i_flag |= IN_CHANGE;
                vput(fvp);
        } else
                vrele(fvp);
        return (error);
}

/*
 * Mkdir system call
 */
int
ext2fs_mkdir(void *v)
{
        struct vop_mkdir_args *ap = v;
        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 ext2fs_dirtemplate dirtemplate;
        mode_t dmode;
        int error;

#ifdef DIAGNOSTIC
        if ((cnp->cn_flags & HASBUF) == 0)
                panic("ext2fs_mkdir: no name");
#endif
        dp = VTOI(dvp);
        if ((nlink_t)dp->i_e2fs_nlink >= LINK_MAX) {
                error = EMLINK;
                goto out;
        }
        dmode = vap->va_mode & ACCESSPERMS;
        dmode |= IFDIR;
        /*
         * Must simulate part of ext2fs_makeinode here to acquire the inode,
         * but not have it entered in the parent directory. The entry is
         * made later after writing "." and ".." entries.
         */
        if ((error = ext2fs_inode_alloc(dp, dmode, cnp->cn_cred, &tvp)) != 0)
                goto out;
        ip = VTOI(tvp);
        ip->i_e2fs_uid = cnp->cn_cred->cr_uid;
        ip->i_e2fs_gid = dp->i_e2fs_gid;
        ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
        ip->i_e2fs_mode = dmode;
        tvp->v_type = VDIR;     /* Rest init'd in getnewvnode(). */
        ip->i_e2fs_nlink = 2;
        error = ext2fs_update(ip, 1);

        /*
         * 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_e2fs_nlink++;
        dp->i_flag |= IN_CHANGE;
        if ((error = ext2fs_update(dp, 1)) != 0)
                goto bad;

        /* Initialize directory with "." and ".." from static template. */
        memset(&dirtemplate, 0, sizeof(dirtemplate));
        dirtemplate.dot_ino = htole32(ip->i_number);
        dirtemplate.dot_reclen = htole16(12);
        dirtemplate.dot_namlen = 1;
        if (ip->i_e2fs->e2fs.e2fs_rev > E2FS_REV0 &&
            (ip->i_e2fs->e2fs.e2fs_features_incompat & EXT2F_INCOMPAT_FTYPE)) {
                dirtemplate.dot_type = EXT2_FT_DIR;
        }
        dirtemplate.dot_name[0] = '.';
        dirtemplate.dotdot_ino = htole32(dp->i_number);
        dirtemplate.dotdot_reclen = htole16(VTOI(dvp)->i_e2fs->e2fs_bsize - 12);
        dirtemplate.dotdot_namlen = 2;
        if (ip->i_e2fs->e2fs.e2fs_rev > E2FS_REV0 &&
            (ip->i_e2fs->e2fs.e2fs_features_incompat & EXT2F_INCOMPAT_FTYPE)) {
                dirtemplate.dotdot_type = EXT2_FT_DIR;
        }
        dirtemplate.dotdot_name[0] = dirtemplate.dotdot_name[1] = '.';
        error = vn_rdwr(UIO_WRITE, tvp, (caddr_t)&dirtemplate,
            sizeof (dirtemplate), (off_t)0, UIO_SYSSPACE,
            IO_NODELOCKED|IO_SYNC, cnp->cn_cred, NULL, curproc);
        if (error) {
                dp->i_e2fs_nlink--;
                dp->i_flag |= IN_CHANGE;
                goto bad;
        }
        if (VTOI(dvp)->i_e2fs->e2fs_bsize >
                                                        VFSTOUFS(dvp->v_mount)->um_mountp->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) {
                        dp->i_e2fs_nlink--;
                        dp->i_flag |= IN_CHANGE;
                        goto bad;
                }
                ip->i_flag |= IN_CHANGE;
        }

        /* Directory set up, now install its entry in the parent directory. */
        error = ext2fs_direnter(ip, dvp, cnp);
        if (error != 0) {
                dp->i_e2fs_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_e2fs_nlink = 0;
                ip->i_flag |= IN_CHANGE;
                vput(tvp);
        } else
                *ap->a_vpp = tvp;
out:
        pool_put(&namei_pool, cnp->cn_pnbuf);
        vput(dvp);
        return (error);
}

/*
 * Rmdir system call.
 */
int
ext2fs_rmdir(void *v)
{
        struct vop_rmdir_args *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;

        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_e2fs_nlink != 2 ||
            !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, cnp);
        if (error != 0)
                goto out;
        dp->i_e2fs_nlink--;
        dp->i_flag |= IN_CHANGE;
        cache_purge(dvp);
        vput(dvp);
        dvp = NULL;
        /*
         * 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(ip, (off_t)0, IO_SYNC, cnp->cn_cred);
        cache_purge(ITOV(ip));
out:
        if (dvp)
                vput(dvp);
        vput(vp);
        return (error);
}

/*
 * symlink -- make a symbolic link
 */
int
ext2fs_symlink(void *v)
{
        struct vop_symlink_args *ap = v;
        struct vnode *vp, **vpp = ap->a_vpp;
        struct inode *ip;
        int len, error;

        error = ext2fs_makeinode(IFLNK | ap->a_vap->va_mode, ap->a_dvp,
                              vpp, ap->a_cnp);
        vput(ap->a_dvp);
        if (error)
                return (error);
        vp = *vpp;
        len = strlen(ap->a_target);
        if (len < EXT2_MAXSYMLINKLEN) {
                ip = VTOI(vp);
                memcpy(ip->i_e2din->e2di_shortlink, ap->a_target, len);
                error = ext2fs_setsize(ip, len);
                if (error)
                        goto bad;
                ip->i_flag |= IN_CHANGE | IN_UPDATE;
        } else
                error = vn_rdwr(UIO_WRITE, vp, ap->a_target, len, (off_t)0,
                    UIO_SYSSPACE, IO_NODELOCKED, ap->a_cnp->cn_cred, NULL,
                    curproc);
bad:
        vput(vp);
        return (error);
}

/*
 * Return target name of a symbolic link
 */
int
ext2fs_readlink(void *v)
{
        struct vop_readlink_args *ap = v;
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        u_int64_t isize;

        isize = ext2fs_size(ip);
        if (isize < EXT2_MAXSYMLINKLEN) {
                return (uiomove((char *)ip->i_e2din->e2di_shortlink, isize,
                    ap->a_uio));
        }
        return (VOP_READ(vp, ap->a_uio, 0, ap->a_cred));
}

/*
 * Return POSIX pathconf information applicable to ext2 filesystems.
 */
int
ext2fs_pathconf(void *v)
{
        struct vop_pathconf_args *ap = v;
        int error = 0;

        switch (ap->a_name) {
        case _PC_TIMESTAMP_RESOLUTION:
                *ap->a_retval = 1000000000;     /* 1 billion nanoseconds */
                break;
        default:
                return (ufs_pathconf(v));
        }

        return (error);
}

/*
 * Advisory record locking support
 */
int
ext2fs_advlock(void *v)
{
        struct vop_advlock_args *ap = v;
        struct inode *ip = VTOI(ap->a_vp);

        return (lf_advlock(&ip->i_lockf, ext2fs_size(ip), ap->a_id, ap->a_op,
            ap->a_fl, ap->a_flags));
}

/*
 * Allocate a new inode.
 */
int
ext2fs_makeinode(int mode, struct vnode *dvp, struct vnode **vpp,
    struct componentname *cnp)
{
        struct inode *ip, *pdir;
        struct vnode *tvp;
        int error;

        pdir = VTOI(dvp);
#ifdef DIAGNOSTIC
        if ((cnp->cn_flags & HASBUF) == 0)
                panic("ext2fs_makeinode: no name");
#endif
        *vpp = NULL;
        if ((mode & IFMT) == 0)
                mode |= IFREG;

        if ((error = ext2fs_inode_alloc(pdir, mode, cnp->cn_cred, &tvp))
            != 0) {
                pool_put(&namei_pool, cnp->cn_pnbuf);
                return (error);
        }
        ip = VTOI(tvp);
        ip->i_e2fs_gid = pdir->i_e2fs_gid;
        ip->i_e2fs_uid = cnp->cn_cred->cr_uid;
        ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
        ip->i_e2fs_mode = mode;
        tvp->v_type = IFTOVT(mode);     /* Rest init'd in getnewvnode(). */
        ip->i_e2fs_nlink = 1;
        if ((ip->i_e2fs_mode & ISGID) &&
                !groupmember(ip->i_e2fs_gid, cnp->cn_cred) &&
            suser_ucred(cnp->cn_cred))
                ip->i_e2fs_mode &= ~ISGID;

        /*
         * Make sure inode goes to disk before directory entry.
         */
        if ((error = ext2fs_update(ip, 1)) != 0)
                goto bad;
        error = ext2fs_direnter(ip, dvp, cnp);
        if (error != 0)
                goto bad;
        if ((cnp->cn_flags & SAVESTART) == 0)
                pool_put(&namei_pool, cnp->cn_pnbuf);
        *vpp = tvp;
        return (0);

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

/*
 * Synch an open file.
 */
int
ext2fs_fsync(void *v)
{
        struct vop_fsync_args *ap = v;
        struct vnode *vp = ap->a_vp;

        vflushbuf(vp, ap->a_waitfor == MNT_WAIT);
        return (ext2fs_update(VTOI(ap->a_vp), ap->a_waitfor == MNT_WAIT));
}

/*
 * Reclaim an inode so that it can be used for other purposes.
 */
int
ext2fs_reclaim(void *v)
{
        struct vop_reclaim_args *ap = v;
        struct vnode *vp = ap->a_vp;
        struct inode *ip;
#ifdef DIAGNOSTIC
        extern int prtactive;

        if (prtactive && vp->v_usecount != 0)
                vprint("ext2fs_reclaim: pushing active", vp);
#endif

        /*
         * Remove the inode from its hash chain.
         */
        ip = VTOI(vp);
        ufs_ihashrem(ip);

        /*
         * Purge old data structures associated with the inode.
         */
        cache_purge(vp);
        if (ip->i_devvp)
                vrele(ip->i_devvp);

        if (ip->i_e2din != NULL)
                pool_put(&ext2fs_dinode_pool, ip->i_e2din);

        pool_put(&ext2fs_inode_pool, ip);

        vp->v_data = NULL;

        return (0);
}

/* Global vfs data structures for ext2fs. */
const struct vops ext2fs_vops = {
        .vop_lookup     = ext2fs_lookup,
        .vop_create     = ext2fs_create,
        .vop_mknod      = ext2fs_mknod,
        .vop_open       = ext2fs_open,
        .vop_close      = ufs_close,
        .vop_access     = ext2fs_access,
        .vop_getattr    = ext2fs_getattr,
        .vop_setattr    = ext2fs_setattr,
        .vop_read       = ext2fs_read,
        .vop_write      = ext2fs_write,
        .vop_ioctl      = ufs_ioctl,
        .vop_kqfilter   = ufs_kqfilter,
        .vop_revoke     = NULL,
        .vop_fsync      = ext2fs_fsync,
        .vop_remove     = ext2fs_remove,
        .vop_link       = ext2fs_link,
        .vop_rename     = ext2fs_rename,
        .vop_mkdir      = ext2fs_mkdir,
        .vop_rmdir      = ext2fs_rmdir,
        .vop_symlink    = ext2fs_symlink,
        .vop_readdir    = ext2fs_readdir,
        .vop_readlink   = ext2fs_readlink,
        .vop_abortop    = vop_generic_abortop,
        .vop_inactive   = ext2fs_inactive,
        .vop_reclaim    = ext2fs_reclaim,
        .vop_lock       = ufs_lock,
        .vop_unlock     = ufs_unlock,
        .vop_bmap       = ext2fs_bmap,
        .vop_strategy   = ufs_strategy,
        .vop_print      = ufs_print,
        .vop_islocked   = ufs_islocked,
        .vop_pathconf   = ext2fs_pathconf,
        .vop_advlock    = ext2fs_advlock,
        .vop_bwrite     = vop_generic_bwrite,
};

const struct vops ext2fs_specvops = {
        .vop_close      = ufsspec_close,
        .vop_access     = ext2fs_access,
        .vop_getattr    = ext2fs_getattr,
        .vop_setattr    = ext2fs_setattr,
        .vop_read       = ufsspec_read,
        .vop_write      = ufsspec_write,
        .vop_fsync      = ext2fs_fsync,
        .vop_inactive   = ext2fs_inactive,
        .vop_reclaim    = ext2fs_reclaim,
        .vop_lock       = ufs_lock,
        .vop_unlock     = ufs_unlock,
        .vop_print      = ufs_print,
        .vop_islocked   = ufs_islocked,

        /* XXX: Keep in sync with spec_vops. */
        .vop_lookup     = vop_generic_lookup,
        .vop_create     = vop_generic_badop,
        .vop_mknod      = vop_generic_badop,
        .vop_open       = spec_open,
        .vop_ioctl      = spec_ioctl,
        .vop_kqfilter   = spec_kqfilter,
        .vop_revoke     = vop_generic_revoke,
        .vop_remove     = vop_generic_badop,
        .vop_link       = vop_generic_badop,
        .vop_rename     = vop_generic_badop,
        .vop_mkdir      = vop_generic_badop,
        .vop_rmdir      = vop_generic_badop,
        .vop_symlink    = vop_generic_badop,
        .vop_readdir    = vop_generic_badop,
        .vop_readlink   = vop_generic_badop,
        .vop_abortop    = vop_generic_badop,
        .vop_bmap       = vop_generic_bmap,
        .vop_strategy   = spec_strategy,
        .vop_pathconf   = spec_pathconf,
        .vop_advlock    = spec_advlock,
        .vop_bwrite     = vop_generic_bwrite,
};

#ifdef FIFO
const struct vops ext2fs_fifovops = {
        .vop_close      = ufsfifo_close,
        .vop_access     = ufsfifo_close,
        .vop_getattr    = ext2fs_getattr,
        .vop_setattr    = ext2fs_setattr,
        .vop_read       = ufsfifo_read,
        .vop_write      = ufsfifo_write,
        .vop_fsync      = ext2fs_fsync,
        .vop_inactive   = ext2fs_inactive,
        .vop_reclaim    = ext2fsfifo_reclaim,
        .vop_lock       = ufs_lock,
        .vop_unlock     = ufs_unlock,
        .vop_print      = ufs_print,
        .vop_islocked   = ufs_islocked,
        .vop_bwrite     = vop_generic_bwrite,

        /* XXX: Keep in sync with fifo_vops */
        .vop_lookup     = vop_generic_lookup,
        .vop_create     = vop_generic_badop,
        .vop_mknod      = vop_generic_badop,
        .vop_open       = fifo_open,
        .vop_ioctl      = fifo_ioctl,
        .vop_kqfilter   = fifo_kqfilter,
        .vop_revoke     = vop_generic_revoke,
        .vop_remove     = vop_generic_badop,
        .vop_link       = vop_generic_badop,
        .vop_rename     = vop_generic_badop,
        .vop_mkdir      = vop_generic_badop,
        .vop_rmdir      = vop_generic_badop,
        .vop_symlink    = vop_generic_badop,
        .vop_readdir    = vop_generic_badop,
        .vop_readlink   = vop_generic_badop,
        .vop_abortop    = vop_generic_badop,
        .vop_bmap       = vop_generic_bmap,
        .vop_strategy   = vop_generic_badop,
        .vop_pathconf   = fifo_pathconf,
        .vop_advlock    = fifo_advlock,
};

int
ext2fsfifo_reclaim(void *v)
{
        fifo_reclaim(v);
        return (ext2fs_reclaim(v));
}
#endif /* FIFO */