vfs_syscalls.c:

[FreeBSD/FreeBSD.git] / sys / 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 8.7 (Berkeley) 2/3/94
 *      @(#)ufs_vnops.c 8.27 (Berkeley) 5/27/95
 * $FreeBSD$
 */

#include "opt_suiddir.h"

#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/bio.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/unistd.h>
#include <sys/time.h>
#include <sys/vnode.h>
#include <sys/namei.h>
#include <sys/lockf.h>
#include <sys/event.h>
#include <sys/conf.h>
#include <sys/file.h>

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

#include <fs/fifofs/fifo.h>

#include <sys/signalvar.h>
#include <ufs/ufs/dir.h>

#include <gnu/ext2fs/inode.h>
#include <gnu/ext2fs/ext2_mount.h>
#include <gnu/ext2fs/ext2_fs_sb.h>
#include <gnu/ext2fs/fs.h>
#include <gnu/ext2fs/ext2_extern.h>
#include <gnu/ext2fs/ext2_fs.h>

static int ext2_makeinode(int mode, struct vnode *, struct vnode **, struct componentname *);

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 *, struct thread *);
static int ext2_chown(struct vnode *, uid_t, gid_t, struct ucred *,
    struct thread *);
static int ext2_close(struct vop_close_args *);
static int ext2_create(struct vop_create_args *);
static int ext2_fsync(struct vop_fsync_args *);
static int ext2_getattr(struct vop_getattr_args *);
static int ext2_kqfilter(struct vop_kqfilter_args *ap);
static int ext2_link(struct vop_link_args *);
static int ext2_mkdir(struct vop_mkdir_args *);
static int ext2_mknod(struct vop_mknod_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_read(struct vop_read_args *);
static int ext2_readlink(struct vop_readlink_args *);
static int ext2_remove(struct vop_remove_args *);
static int ext2_rename(struct vop_rename_args *);
static int ext2_rmdir(struct vop_rmdir_args *);
static int ext2_setattr(struct vop_setattr_args *);
static int ext2_strategy(struct vop_strategy_args *);
static int ext2_symlink(struct vop_symlink_args *);
static int ext2_write(struct vop_write_args *);
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 ext2spec_close(struct vop_close_args *);
static int ext2spec_read(struct vop_read_args *);
static int ext2spec_write(struct vop_write_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);

/* Global vfs data structures for ext2. */
vop_t **ext2_vnodeop_p;
static struct vnodeopv_entry_desc ext2_vnodeop_entries[] = {
        { &vop_default_desc,            (vop_t *) vop_defaultop },
        { &vop_access_desc,             (vop_t *) ext2_access },
        { &vop_advlock_desc,            (vop_t *) ext2_advlock },
        { &vop_bmap_desc,               (vop_t *) ext2_bmap },
        { &vop_cachedlookup_desc,       (vop_t *) ext2_lookup },
        { &vop_close_desc,              (vop_t *) ext2_close },
        { &vop_create_desc,             (vop_t *) ext2_create },
        { &vop_fsync_desc,              (vop_t *) ext2_fsync },
        { &vop_getattr_desc,            (vop_t *) ext2_getattr },
        { &vop_getwritemount_desc,      (vop_t *) vop_stdgetwritemount },
        { &vop_inactive_desc,           (vop_t *) ext2_inactive },
        { &vop_islocked_desc,           (vop_t *) vop_stdislocked },
        { &vop_link_desc,               (vop_t *) ext2_link },
        { &vop_lock_desc,               (vop_t *) vop_stdlock },
        { &vop_lookup_desc,             (vop_t *) vfs_cache_lookup },
        { &vop_mkdir_desc,              (vop_t *) ext2_mkdir },
        { &vop_mknod_desc,              (vop_t *) ext2_mknod },
        { &vop_open_desc,               (vop_t *) ext2_open },
        { &vop_pathconf_desc,           (vop_t *) ext2_pathconf },
        { &vop_poll_desc,               (vop_t *) vop_stdpoll },
        { &vop_kqfilter_desc,           (vop_t *) ext2_kqfilter },
        { &vop_print_desc,              (vop_t *) ext2_print },
        { &vop_read_desc,               (vop_t *) ext2_read },
        { &vop_readdir_desc,            (vop_t *) ext2_readdir },
        { &vop_readlink_desc,           (vop_t *) ext2_readlink },
        { &vop_reallocblks_desc,        (vop_t *) ext2_reallocblks },
        { &vop_reclaim_desc,            (vop_t *) ext2_reclaim },
        { &vop_remove_desc,             (vop_t *) ext2_remove },
        { &vop_rename_desc,             (vop_t *) ext2_rename },
        { &vop_rmdir_desc,              (vop_t *) ext2_rmdir },
        { &vop_setattr_desc,            (vop_t *) ext2_setattr },
        { &vop_strategy_desc,           (vop_t *) ext2_strategy },
        { &vop_symlink_desc,            (vop_t *) ext2_symlink },
        { &vop_unlock_desc,             (vop_t *) vop_stdunlock },
        { &vop_write_desc,              (vop_t *) ext2_write },
        { NULL, NULL }
};
static struct vnodeopv_desc ext2fs_vnodeop_opv_desc =
        { &ext2_vnodeop_p, ext2_vnodeop_entries };

vop_t **ext2_specop_p;
static struct vnodeopv_entry_desc ext2_specop_entries[] = {
        { &vop_default_desc,            (vop_t *) spec_vnoperate },
        { &vop_access_desc,             (vop_t *) ext2_access },
        { &vop_close_desc,              (vop_t *) ext2spec_close },
        { &vop_fsync_desc,              (vop_t *) ext2_fsync },
        { &vop_getattr_desc,            (vop_t *) ext2_getattr },
        { &vop_inactive_desc,           (vop_t *) ext2_inactive },
        { &vop_islocked_desc,           (vop_t *) vop_stdislocked },
        { &vop_lock_desc,               (vop_t *) vop_stdlock },
        { &vop_print_desc,              (vop_t *) ext2_print },
        { &vop_read_desc,               (vop_t *) ext2spec_read },
        { &vop_reclaim_desc,            (vop_t *) ext2_reclaim },
        { &vop_setattr_desc,            (vop_t *) ext2_setattr },
        { &vop_unlock_desc,             (vop_t *) vop_stdunlock },
        { &vop_write_desc,              (vop_t *) ext2spec_write },
        { NULL, NULL }
};
static struct vnodeopv_desc ext2fs_specop_opv_desc =
        { &ext2_specop_p, ext2_specop_entries };

vop_t **ext2_fifoop_p;
static struct vnodeopv_entry_desc ext2_fifoop_entries[] = {
        { &vop_default_desc,            (vop_t *) fifo_vnoperate },
        { &vop_access_desc,             (vop_t *) ext2_access },
        { &vop_close_desc,              (vop_t *) ext2fifo_close },
        { &vop_fsync_desc,              (vop_t *) ext2_fsync },
        { &vop_getattr_desc,            (vop_t *) ext2_getattr },
        { &vop_inactive_desc,           (vop_t *) ext2_inactive },
        { &vop_islocked_desc,           (vop_t *) vop_stdislocked },
        { &vop_kqfilter_desc,           (vop_t *) ext2fifo_kqfilter },
        { &vop_lock_desc,               (vop_t *) vop_stdlock },
        { &vop_print_desc,              (vop_t *) ext2_print },
        { &vop_read_desc,               (vop_t *) ext2fifo_read },
        { &vop_reclaim_desc,            (vop_t *) ext2_reclaim },
        { &vop_setattr_desc,            (vop_t *) ext2_setattr },
        { &vop_unlock_desc,             (vop_t *) vop_stdunlock },
        { &vop_write_desc,              (vop_t *) ext2fifo_write },
        { NULL, NULL }
};
static struct vnodeopv_desc ext2fs_fifoop_opv_desc =
        { &ext2_fifoop_p, ext2_fifoop_entries };

        VNODEOP_SET(ext2fs_vnodeop_opv_desc);
        VNODEOP_SET(ext2fs_specop_opv_desc);
        VNODEOP_SET(ext2fs_fifoop_opv_desc);

#include <gnu/ext2fs/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; \
}

/*
 * A virgin directory (no blushing please).
 * Note that the type and namlen fields are reversed relative to ext2.
 * Also, we don't use `struct odirtemplate', since it would just cause
 * endianness problems.
 */
static struct dirtemplate mastertemplate = {
        0, 12, 1, EXT2_FT_DIR, ".",
        0, DIRBLKSIZ - 12, 2, EXT2_FT_DIR, ".."
};
static struct dirtemplate omastertemplate = {
        0, 12, 1, EXT2_FT_UNKNOWN, ".",
        0, DIRBLKSIZ - 12, 2, EXT2_FT_UNKNOWN, ".."
};

void
ext2_itimes(vp)
        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))
                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);
}

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

/*
 * Open called.
 *
 * Nothing to do.
 */
int
ext2_open(ap)
        struct vop_open_args /* {
                struct vnode *a_vp;
                int  a_mode;
                struct ucred *a_cred;
                struct thread *a_td;
        } */ *ap;
{

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

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

        mtx_lock(&vp->v_interlock);
        if (vp->v_usecount > 1) {
                ext2_itimes(vp);
                mtx_unlock(&vp->v_interlock);
        } else {
                mtx_unlock(&vp->v_interlock);
                /*
                 * If we are closing the last reference to an unlinked
                 * file, then it will be freed by the inactive routine.
                 * Because the freeing causes a the filesystem to be
                 * modified, it must be held up during periods when the
                 * filesystem is suspended.
                 *
                 * XXX - EAGAIN is returned to prevent vn_close from
                 * repeating the vrele operation.
                 */
                if (vp->v_type == VREG && VTOI(vp)->i_nlink == 0) {
                        (void) vn_start_write(vp, &mp, V_WAIT);
                        vrele(vp);
                        vn_finished_write(mp);
                        return (EAGAIN);
                }
        }
        return (0);
}

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

        /*
         * 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_flags & (IMMUTABLE | SF_SNAPSHOT)))
                return (EPERM);

        error = vaccess(vp->v_type, ip->i_mode, ip->i_uid, ip->i_gid,
            ap->a_mode, ap->a_cred, NULL);
        return (error);
}

static int
ext2_getattr(ap)
        struct vop_getattr_args /* {
                struct vnode *a_vp;
                struct vattr *a_vap;
                struct ucred *a_cred;
                struct thread *a_td;
        } */ *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 = ip->i_nlink;
        vap->va_uid = ip->i_uid;
        vap->va_gid = ip->i_gid;
        vap->va_rdev = ip->i_rdev;
        vap->va_size = ip->i_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
 */
int
ext2_setattr(ap)
        struct vop_setattr_args /* {
                struct vnode *a_vp;
                struct vattr *a_vap;
                struct ucred *a_cred;
                struct thread *a_td;
        } */ *ap;
{
        struct vattr *vap = ap->a_vap;
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        struct ucred *cred = ap->a_cred;
        struct thread *td = ap->a_td;
        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);
                /*
                 * Callers may only modify the file flags on objects they
                 * have VADMIN rights for.
                 */
                if ((error = VOP_ACCESS(vp, VADMIN, cred, td)))
                        return (error);
                /*
                 * Unprivileged processes and privileged processes in
                 * jail() are not permitted to unset system flags, or
                 * modify flags if any system flags are set.
                 * Privileged non-jail processes may not modify system flags
                 * if securelevel > 0 and any existing system flags are set.
                 */
                if (!suser_cred(cred, PRISON_ROOT)) {
                        if (ip->i_flags
                            & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND)) {
                                error = securelevel_gt(cred, 0);
                                if (error)
                                        return (error);
                        }
                        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,
                    td)) != 0)
                        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);
                        break;
                default:
                        break;
                }
                if ((error = ext2_truncate(vp, vap->va_size, 0, cred, td)) != 0)
                        return (error);
        }
        if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
                if (vp->v_mount->mnt_flag & MNT_RDONLY)
                        return (EROFS);
                /*
                 * From utimes(2):
                 * If times is NULL, ... The caller must be the owner of
                 * the file, have permission to write the file, or be the
                 * super-user.
                 * If times is non-NULL, ... The caller must be the owner of
                 * the file or be the super-user.
                 */
                if ((error = VOP_ACCESS(vp, VADMIN, cred, td)) &&
                    ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
                    (error = VOP_ACCESS(vp, VWRITE, cred, td))))
                        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, td);
        }
        VN_KNOTE(vp, NOTE_ATTRIB);
        return (error);
}

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

        /*
         * To modify the permissions on a file, must possess VADMIN
         * for that file.
         */
        if ((error = VOP_ACCESS(vp, VADMIN, cred, td)))
                return (error);
        /*
         * Privileged processes may set the sticky bit on non-directories,
         * as well as set the setgid bit on a file with a group that the
         * process is not a member of.
         */
        if (suser_cred(cred, PRISON_ROOT)) {
                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(vp, uid, gid, cred, td)
        struct vnode *vp;
        uid_t uid;
        gid_t gid;
        struct ucred *cred;
        struct thread *td;
{
        struct inode *ip = VTOI(vp);
        uid_t ouid;
        gid_t ogid;
        int error = 0;

        if (uid == (uid_t)VNOVAL)
                uid = ip->i_uid;
        if (gid == (gid_t)VNOVAL)
                gid = ip->i_gid;
        /*
         * To modify the ownership of a file, must possess VADMIN
         * for that file.
         */
        if ((error = VOP_ACCESS(vp, VADMIN, cred, td)))
                return (error);
        /*
         * To change the owner of a file, or change the group of a file
         * to a group of which we are not a member, the caller must
         * have privilege.
         */
        if ((uid != ip->i_uid || 
            (gid != ip->i_gid && !groupmember(gid, cred))) &&
            (error = suser_cred(cred, PRISON_ROOT)))
                return (error);
        ogid = ip->i_gid;
        ouid = ip->i_uid;
        ip->i_gid = gid;
        ip->i_uid = uid;
        ip->i_flag |= IN_CHANGE;
        if (suser_cred(cred, PRISON_ROOT) && (ouid != uid || ogid != gid))
                ip->i_mode &= ~(ISUID | ISGID);
        return (0);
}

/*
 * Synch an open file.
 */
/* ARGSUSED */
static int
ext2_fsync(ap)
        struct vop_fsync_args /* {
                struct vnode *a_vp;
                struct ucred *a_cred;
                int a_waitfor;
                struct thread *a_td;
        } */ *ap;
{
        struct vnode *vp = ap->a_vp;
        struct buf *bp;
        struct buf *nbp;
        int s;

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

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

loop:
        s = splbio();
        for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
                nbp = TAILQ_NEXT(bp, b_vnbufs);
                if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT))
                        continue;
                if ((bp->b_flags & B_DELWRI) == 0)
                        panic("ext2_fsync: not dirty");
                bremfree(bp);
                splx(s);
                /*
                 * 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 == vp || ap->a_waitfor == MNT_NOWAIT)
                        (void) bawrite(bp);
                else
                        (void) bwrite(bp);
                goto loop;
        }
        if (ap->a_waitfor == MNT_WAIT) {
                VI_LOCK(vp);
                while (vp->v_numoutput) {
                        vp->v_iflag |= VI_BWAIT;
                        msleep(&vp->v_numoutput, VI_MTX(vp), 
                            PRIBIO + 1, "e2fsyn", 0);
                }
                VI_UNLOCK(vp);
#if DIAGNOSTIC
                if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
                        vprint("ext2_fsync: dirty", vp);
                        goto loop;
                }
#endif
        }
        splx(s);
        return (ext2_update(ap->a_vp, ap->a_waitfor == MNT_WAIT));
}

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

        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_rdev != VNOVAL) {
                /*
                 * Want to be able to use this to make badblock
                 * inodes, so don't truncate the dev number.
                 */
                ip->i_rdev = vap->va_rdev;
        }
        /*
         * 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.
         */
        vput(*vpp);
        (*vpp)->v_type = VNON;
        ino = ip->i_number;     /* Save this before vgone() invalidates ip. */
        vgone(*vpp);
        error = VFS_VGET(ap->a_dvp->v_mount, ino, LK_EXCLUSIVE, vpp);
        if (error) {
                *vpp = NULL;
                return (error);
        }
        return (0);
}

static int
ext2_remove(ap)
        struct vop_remove_args /* {
                struct vnode *a_dvp;
                struct vnode *a_vp;
                struct componentname *a_cnp;
        } */ *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
 */
static int
ext2_link(ap)
        struct vop_link_args /* {
                struct vnode *a_tdvp;
                struct vnode *a_vp;
                struct componentname *a_cnp;
        } */ *ap;
{
        struct vnode *vp = ap->a_vp;
        struct vnode *tdvp = ap->a_tdvp;
        struct componentname *cnp = ap->a_cnp;
        struct thread *td = cnp->cn_thread;
        struct inode *ip;
        int error;

#ifdef DIAGNOSTIC
        if ((cnp->cn_flags & HASBUF) == 0)
                panic("ext2_link: no name");
#endif
        if (tdvp->v_mount != vp->v_mount) {
                error = EXDEV;
                goto out2;
        }
        if (tdvp != vp && (error = vn_lock(vp, LK_EXCLUSIVE, td))) {
                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)
                VOP_UNLOCK(vp, 0, td);
out2:
        return (error);
}

/*
 * Rename system call.
 *   See comments in sys/ufs/ufs/ufs_vnops.c
 */
static int
ext2_rename(ap)
        struct vop_rename_args  /* {
                struct vnode *a_fdvp;
                struct vnode *a_fvp;
                struct componentname *a_fcnp;
                struct vnode *a_tdvp;
                struct vnode *a_tvp;
                struct componentname *a_tcnp;
        } */ *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 thread *td = fcnp->cn_thread;
        struct inode *ip, *xp, *dp;
        struct dirtemplate dirbuf;
        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("ext2_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:
                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) {
                printf("ext2_rename: fvp == tvp (can't happen)\n");
                error = 0;
                goto abortit;
        }

        if ((error = vn_lock(fvp, LK_EXCLUSIVE, td)) != 0)
                goto abortit;
        dp = VTOI(fdvp);
        ip = VTOI(fvp);
        if (ip->i_nlink >= LINK_MAX) {
                VOP_UNLOCK(fvp, 0, td);
                error = EMLINK;
                goto abortit;
        }
        if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))
            || (dp->i_flags & APPEND)) {
                VOP_UNLOCK(fvp, 0, td);
                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) & ISDOTDOT ||
                    (ip->i_flag & IN_RENAME)) {
                        VOP_UNLOCK(fvp, 0, td);
                        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_nlink++;
        ip->i_flag |= IN_CHANGE;
        if ((error = ext2_update(fvp, 1)) != 0) {
                VOP_UNLOCK(fvp, 0, td);
                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_ACCESS(fvp, VWRITE, tcnp->cn_cred, tcnp->cn_thread);
        VOP_UNLOCK(fvp, 0, td);
        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 = ext2_checkpath(ip, dp, tcnp->cn_cred);
                if (error)
                        goto out;
                VREF(tdvp);
                error = relookup(tdvp, &tvp, tcnp);
                if (error)
                        goto out;
                vrele(tdvp);
                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("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;
                                (void)ext2_update(tdvp, 1);
                        }
                        goto bad;
                }
                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;
                        }
                        cache_purge(tdvp);
                } 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;
                }
                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, tcnp->cn_thread);
                }
                xp->i_flag |= IN_CHANGE;
                vput(tvp);
                xp = NULL;
        }

        /*
         * 3) Unlink the source.
         */
        fcnp->cn_flags &= ~MODMASK;
        fcnp->cn_flags |= LOCKPARENT | LOCKLEAF;
        VREF(fdvp);
        error = relookup(fdvp, &fvp, fcnp);
        if (error == 0)
                vrele(fdvp);
        if (fvp != NULL) {
                xp = VTOI(fvp);
                dp = VTOI(fdvp);
        } else {
                /*
                 * From name has disappeared.
                 */
                if (doingdirectory)
                        panic("ext2_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 IN_RENAME flag ensures that it cannot be moved by another
         * rename.
         */
        if (xp != ip) {
                if (doingdirectory)
                        panic("ext2_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_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 | IO_NOMACCHECK,
                                tcnp->cn_cred, NOCRED, (int *)0,
                                (struct thread *)0);
                        if (error == 0) {
                                /* Like ufs 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;
                                        (void) vn_rdwr(UIO_WRITE, fvp,
                                            (caddr_t)&dirbuf,
                                            sizeof (struct dirtemplate),
                                            (off_t)0, UIO_SYSSPACE,
                                            IO_NODELOCKED | IO_SYNC |
                                            IO_NOMACCHECK, tcnp->cn_cred,
                                            NOCRED, (int *)0,
                                            (struct thread *)0);
                                        cache_purge(fdvp);
                                }
                        }
                }
                error = ext2_dirremove(fdvp, fcnp);
                if (!error) {
                        xp->i_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, td) == 0) {
                ip->i_nlink--;
                ip->i_flag |= IN_CHANGE;
                ip->i_flag &= ~IN_RENAME;
                vput(fvp);
        } else
                vrele(fvp);
        return (error);
}

/*
 * Mkdir system call
 */
static int
ext2_mkdir(ap)
        struct vop_mkdir_args /* {
                struct vnode *a_dvp;
                struct vnode **a_vpp;
                struct componentname *a_cnp;
                struct vattr *a_vap;
        } */ *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;

#ifdef DIAGNOSTIC
        if ((cnp->cn_flags & HASBUF) == 0)
                panic("ext2_mkdir: no name");
#endif
        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
        {
                /*
                 * 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;
                } else {
                        ip->i_uid = cnp->cn_cred->cr_uid;
                }
        }
#else
        ip->i_uid = cnp->cn_cred->cr_uid;
#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 & ISWHITEOUT)
                ip->i_flags |= UF_OPAQUE;
        error = ext2_update(tvp, 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_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 = &mastertemplate;
        else
                dtp = &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 | IO_NOMACCHECK, cnp->cn_cred, NOCRED,
            (int *)0, (struct thread *)0);
        if (error) {
                dp->i_nlink--;
                dp->i_flag |= IN_CHANGE;
                goto bad;
        }
        if (DIRBLKSIZ > VFSTOEXT2(dvp->v_mount)->um_mountp->mnt_stat.f_bsize)
                /* XXX should grow with balloc() */
                panic("ext2_mkdir: blksize");
        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.
 */
static int
ext2_rmdir(ap)
        struct vop_rmdir_args /* {
                struct vnode *a_dvp;
                struct vnode *a_vp;
                struct componentname *a_cnp;
        } */ *ap;
{
        struct vnode *vp = ap->a_vp;
        struct vnode *dvp = ap->a_dvp;
        struct componentname *cnp = ap->a_cnp;
        struct thread *td = cnp->cn_thread;
        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;
        cache_purge(dvp);
        VOP_UNLOCK(dvp, 0, td);
        /*
         * 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, td);
        cache_purge(ITOV(ip));
        vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, td);
out:
        return (error);
}

/*
 * symlink -- make a symbolic link
 */
static int
ext2_symlink(ap)
        struct vop_symlink_args /* {
                struct vnode *a_dvp;
                struct vnode **a_vpp;
                struct componentname *a_cnp;
                struct vattr *a_vap;
                char *a_target;
        } */ *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
                error = vn_rdwr(UIO_WRITE, vp, ap->a_target, len, (off_t)0,
                    UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK,
                    ap->a_cnp->cn_cred, NOCRED, (int *)0, (struct thread *)0);
        if (error)
                vput(vp);
        return (error);
}

/*
 * Return target name of a symbolic link
 */
static int
ext2_readlink(ap)
        struct vop_readlink_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                struct ucred *a_cred;
        } */ *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) {
                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 ext2_bmaparray() operation may not
 * deadlock on memory.  See ext2_bmap() for details.
 */
int
ext2_strategy(ap)
        struct vop_strategy_args /* {
                struct vnode *a_vp;
                struct buf *a_bp;
        } */ *ap;
{
        struct buf *bp = ap->a_bp;
        struct vnode *vp = ap->a_vp;
        struct inode *ip;
        int32_t blkno;
        int error;

        ip = VTOI(vp);
        if (vp->v_type == VBLK || vp->v_type == VCHR)
                panic("ext2_strategy: spec");
        if (bp->b_blkno == bp->b_lblkno) {
                error = ext2_bmaparray(vp, bp->b_lblkno, &blkno, NULL, NULL);
                bp->b_blkno = blkno;
                if (error) {
                        bp->b_error = error;
                        bp->b_ioflags |= BIO_ERROR;
                        bufdone(bp);
                        return (error);
                }
                if ((long)bp->b_blkno == -1)
                        vfs_bio_clrbuf(bp);
        }
        if ((long)bp->b_blkno == -1) {
                bufdone(bp);
                return (0);
        }
        vp = ip->i_devvp;
        bp->b_dev = vp->v_rdev;
        VOP_STRATEGY(vp, bp);
        return (0);
}

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

        printf("tag VT_UFS, 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);
        printf("\n");
        return (0);
}

/*
 * Read wrapper for special devices.
 */
int
ext2spec_read(ap)
        struct vop_read_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                int  a_ioflag;
                struct ucred *a_cred;
        } */ *ap;
{
        int error, resid;
        struct inode *ip;
        struct uio *uio;

        uio = ap->a_uio;
        resid = uio->uio_resid;
        error = VOCALL(spec_vnodeop_p, VOFFSET(vop_read), ap);
        /*
         * The inode may have been revoked during the call, so it must not
         * be accessed blindly here or in the other wrapper functions.
         */
        ip = VTOI(ap->a_vp);
        if (ip != NULL && (uio->uio_resid != resid || (error == 0 && resid != 0)))
                ip->i_flag |= IN_ACCESS;
        return (error);
}

/*
 * Write wrapper for special devices.
 */
int
ext2spec_write(ap)
        struct vop_write_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                int  a_ioflag;
                struct ucred *a_cred;
        } */ *ap;
{
        int error, resid;
        struct inode *ip;
        struct uio *uio;

        uio = ap->a_uio;
        resid = uio->uio_resid;
        error = VOCALL(spec_vnodeop_p, VOFFSET(vop_write), ap);
        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 special devices.
 *
 * Update the times on the inode then do device close.
 */
int
ext2spec_close(ap)
        struct vop_close_args /* {
                struct vnode *a_vp;
                int  a_fflag;
                struct ucred *a_cred;
                struct thread *a_td;
        } */ *ap;
{
        struct vnode *vp = ap->a_vp;

        mtx_lock(&vp->v_interlock);
        if (vp->v_usecount > 1)
                ext2_itimes(vp);
        mtx_unlock(&vp->v_interlock);
        return (VOCALL(spec_vnodeop_p, VOFFSET(vop_close), ap));
}

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

        uio = ap->a_uio;
        resid = uio->uio_resid;
        error = VOCALL(fifo_vnodeop_p, VOFFSET(vop_read), ap);
        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.
 */
int
ext2fifo_write(ap)
        struct vop_write_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                int  a_ioflag;
                struct ucred *a_cred;
        } */ *ap;
{
        int error, resid;
        struct inode *ip;
        struct uio *uio;

        uio = ap->a_uio;
        resid = uio->uio_resid;
        error = VOCALL(fifo_vnodeop_p, VOFFSET(vop_write), ap);
        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.
 */
int
ext2fifo_close(ap)
        struct vop_close_args /* {
                struct vnode *a_vp;
                int  a_fflag;
                struct ucred *a_cred;
                struct thread *a_td;
        } */ *ap;
{
        struct vnode *vp = ap->a_vp;

        mtx_lock(&vp->v_interlock);
        if (vp->v_usecount > 1)
                ext2_itimes(vp);
        mtx_unlock(&vp->v_interlock);
        return (VOCALL(fifo_vnodeop_p, VOFFSET(vop_close), ap));
}

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

        error = VOCALL(fifo_vnodeop_p, VOFFSET(vop_kqfilter), ap);
        if (error)
                error = ext2_kqfilter(ap);
        return (error);
}

/*
 * Return POSIX pathconf information applicable to ext2 filesystems.
 */
int
ext2_pathconf(ap)
        struct vop_pathconf_args /* {
                struct vnode *a_vp;
                int a_name;
                int *a_retval;
        } */ *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
 */
static int
ext2_advlock(ap)
        struct vop_advlock_args /* {
                struct vnode *a_vp;
                caddr_t  a_id;
                int  a_op;
                struct flock *a_fl;
                int  a_flags;
        } */ *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(mntp, specops, fifoops, vpp)
        struct mount *mntp;
        vop_t **specops;
        vop_t **fifoops;
        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_op = specops;
                vp = addaliasu(vp, ip->i_rdev);
                ip->i_vnode = vp;
                break;
        case VFIFO:
                vp->v_op = fifoops;
                break;
        default:
                break;

        }
        if (ip->i_number == 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 * 4294);
        *vpp = vp;
        return (0);
}

/*
 * Allocate a new inode.
 */
static int
ext2_makeinode(mode, dvp, vpp, cnp)
        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("ext2_makeinode: no name");
#endif
        *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
        {
                /*
                 * 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;
                } else {
                        ip->i_uid = cnp->cn_cred->cr_uid;
                }
        }
#else
        ip->i_uid = cnp->cn_cred->cr_uid;
#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) &&
            suser_cred(cnp->cn_cred, PRISON_ROOT))
                ip->i_mode &= ~ISGID;

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

        /*
         * 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);
}

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 };

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

        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;

        if (vp->v_pollinfo == NULL)
                v_addpollinfo(vp);
        mtx_lock(&vp->v_pollinfo->vpi_lock);
        SLIST_INSERT_HEAD(&vp->v_pollinfo->vpi_selinfo.si_note, kn, kn_selnext);
        mtx_unlock(&vp->v_pollinfo->vpi_lock);

        return (0);
}

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

        KASSERT(vp->v_pollinfo != NULL, ("Mising v_pollinfo"));
        mtx_lock(&vp->v_pollinfo->vpi_lock);
        SLIST_REMOVE(&vp->v_pollinfo->vpi_selinfo.si_note,
            kn, knote, kn_selnext);
        mtx_unlock(&vp->v_pollinfo->vpi_lock);
}

/*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);
}