Use long for the last argument to VOP_PATHCONF rather than a register_t.

[FreeBSD/FreeBSD.git] / sys / kern / vfs_syscalls.c

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 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.
 *
 *      @(#)vfs_syscalls.c      8.13 (Berkeley) 4/15/94
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include "opt_capsicum.h"
#include "opt_compat.h"
#include "opt_ktrace.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/capsicum.h>
#include <sys/disk.h>
#include <sys/sysent.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/sysproto.h>
#include <sys/namei.h>
#include <sys/filedesc.h>
#include <sys/kernel.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/filio.h>
#include <sys/limits.h>
#include <sys/linker.h>
#include <sys/rwlock.h>
#include <sys/sdt.h>
#include <sys/stat.h>
#include <sys/sx.h>
#include <sys/unistd.h>
#include <sys/vnode.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/dirent.h>
#include <sys/jail.h>
#include <sys/syscallsubr.h>
#include <sys/sysctl.h>
#ifdef KTRACE
#include <sys/ktrace.h>
#endif

#include <machine/stdarg.h>

#include <security/audit/audit.h>
#include <security/mac/mac_framework.h>

#include <vm/vm.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/uma.h>

#include <ufs/ufs/quota.h>

MALLOC_DEFINE(M_FADVISE, "fadvise", "posix_fadvise(2) information");

SDT_PROVIDER_DEFINE(vfs);
SDT_PROBE_DEFINE2(vfs, , stat, mode, "char *", "int");
SDT_PROBE_DEFINE2(vfs, , stat, reg, "char *", "int");

static int kern_chflagsat(struct thread *td, int fd, const char *path,
    enum uio_seg pathseg, u_long flags, int atflag);
static int setfflags(struct thread *td, struct vnode *, u_long);
static int getutimes(const struct timeval *, enum uio_seg, struct timespec *);
static int getutimens(const struct timespec *, enum uio_seg,
    struct timespec *, int *);
static int setutimes(struct thread *td, struct vnode *,
    const struct timespec *, int, int);
static int vn_access(struct vnode *vp, int user_flags, struct ucred *cred,
    struct thread *td);

/*
 * Sync each mounted filesystem.
 */
#ifndef _SYS_SYSPROTO_H_
struct sync_args {
        int     dummy;
};
#endif
/* ARGSUSED */
int
sys_sync(struct thread *td, struct sync_args *uap)
{
        struct mount *mp, *nmp;
        int save;

        mtx_lock(&mountlist_mtx);
        for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
                if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) {
                        nmp = TAILQ_NEXT(mp, mnt_list);
                        continue;
                }
                if ((mp->mnt_flag & MNT_RDONLY) == 0 &&
                    vn_start_write(NULL, &mp, V_NOWAIT) == 0) {
                        save = curthread_pflags_set(TDP_SYNCIO);
                        vfs_msync(mp, MNT_NOWAIT);
                        VFS_SYNC(mp, MNT_NOWAIT);
                        curthread_pflags_restore(save);
                        vn_finished_write(mp);
                }
                mtx_lock(&mountlist_mtx);
                nmp = TAILQ_NEXT(mp, mnt_list);
                vfs_unbusy(mp);
        }
        mtx_unlock(&mountlist_mtx);
        return (0);
}

/*
 * Change filesystem quotas.
 */
#ifndef _SYS_SYSPROTO_H_
struct quotactl_args {
        char *path;
        int cmd;
        int uid;
        caddr_t arg;
};
#endif
int
sys_quotactl(struct thread *td, struct quotactl_args *uap)
{
        struct mount *mp;
        struct nameidata nd;
        int error;

        AUDIT_ARG_CMD(uap->cmd);
        AUDIT_ARG_UID(uap->uid);
        if (!prison_allow(td->td_ucred, PR_ALLOW_QUOTAS))
                return (EPERM);
        NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_USERSPACE,
            uap->path, td);
        if ((error = namei(&nd)) != 0)
                return (error);
        NDFREE(&nd, NDF_ONLY_PNBUF);
        mp = nd.ni_vp->v_mount;
        vfs_ref(mp);
        vput(nd.ni_vp);
        error = vfs_busy(mp, 0);
        vfs_rel(mp);
        if (error != 0)
                return (error);
        error = VFS_QUOTACTL(mp, uap->cmd, uap->uid, uap->arg);

        /*
         * Since quota on operation typically needs to open quota
         * file, the Q_QUOTAON handler needs to unbusy the mount point
         * before calling into namei.  Otherwise, unmount might be
         * started between two vfs_busy() invocations (first is our,
         * second is from mount point cross-walk code in lookup()),
         * causing deadlock.
         *
         * Require that Q_QUOTAON handles the vfs_busy() reference on
         * its own, always returning with ubusied mount point.
         */
        if ((uap->cmd >> SUBCMDSHIFT) != Q_QUOTAON)
                vfs_unbusy(mp);
        return (error);
}

/*
 * Used by statfs conversion routines to scale the block size up if
 * necessary so that all of the block counts are <= 'max_size'.  Note
 * that 'max_size' should be a bitmask, i.e. 2^n - 1 for some non-zero
 * value of 'n'.
 */
void
statfs_scale_blocks(struct statfs *sf, long max_size)
{
        uint64_t count;
        int shift;

        KASSERT(powerof2(max_size + 1), ("%s: invalid max_size", __func__));

        /*
         * Attempt to scale the block counts to give a more accurate
         * overview to userland of the ratio of free space to used
         * space.  To do this, find the largest block count and compute
         * a divisor that lets it fit into a signed integer <= max_size.
         */
        if (sf->f_bavail < 0)
                count = -sf->f_bavail;
        else
                count = sf->f_bavail;
        count = MAX(sf->f_blocks, MAX(sf->f_bfree, count));
        if (count <= max_size)
                return;

        count >>= flsl(max_size);
        shift = 0;
        while (count > 0) {
                shift++;
                count >>=1;
        }

        sf->f_bsize <<= shift;
        sf->f_blocks >>= shift;
        sf->f_bfree >>= shift;
        sf->f_bavail >>= shift;
}

static int
kern_do_statfs(struct thread *td, struct mount *mp, struct statfs *buf)
{
        struct statfs *sp;
        int error;

        if (mp == NULL)
                return (EBADF);
        error = vfs_busy(mp, 0);
        vfs_rel(mp);
        if (error != 0)
                return (error);
#ifdef MAC
        error = mac_mount_check_stat(td->td_ucred, mp);
        if (error != 0)
                goto out;
#endif
        /*
         * Set these in case the underlying filesystem fails to do so.
         */
        sp = &mp->mnt_stat;
        sp->f_version = STATFS_VERSION;
        sp->f_namemax = NAME_MAX;
        sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
        error = VFS_STATFS(mp, sp);
        if (error != 0)
                goto out;
        *buf = *sp;
        if (priv_check(td, PRIV_VFS_GENERATION)) {
                buf->f_fsid.val[0] = buf->f_fsid.val[1] = 0;
                prison_enforce_statfs(td->td_ucred, mp, buf);
        }
out:
        vfs_unbusy(mp);
        return (error);
}

/*
 * Get filesystem statistics.
 */
#ifndef _SYS_SYSPROTO_H_
struct statfs_args {
        char *path;
        struct statfs *buf;
};
#endif
int
sys_statfs(struct thread *td, struct statfs_args *uap)
{
        struct statfs *sfp;
        int error;

        sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
        error = kern_statfs(td, uap->path, UIO_USERSPACE, sfp);
        if (error == 0)
                error = copyout(sfp, uap->buf, sizeof(struct statfs));
        free(sfp, M_STATFS);
        return (error);
}

int
kern_statfs(struct thread *td, char *path, enum uio_seg pathseg,
    struct statfs *buf)
{
        struct mount *mp;
        struct nameidata nd;
        int error;

        NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1,
            pathseg, path, td);
        error = namei(&nd);
        if (error != 0)
                return (error);
        mp = nd.ni_vp->v_mount;
        vfs_ref(mp);
        NDFREE(&nd, NDF_ONLY_PNBUF);
        vput(nd.ni_vp);
        return (kern_do_statfs(td, mp, buf));
}

/*
 * Get filesystem statistics.
 */
#ifndef _SYS_SYSPROTO_H_
struct fstatfs_args {
        int fd;
        struct statfs *buf;
};
#endif
int
sys_fstatfs(struct thread *td, struct fstatfs_args *uap)
{
        struct statfs *sfp;
        int error;

        sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
        error = kern_fstatfs(td, uap->fd, sfp);
        if (error == 0)
                error = copyout(sfp, uap->buf, sizeof(struct statfs));
        free(sfp, M_STATFS);
        return (error);
}

int
kern_fstatfs(struct thread *td, int fd, struct statfs *buf)
{
        struct file *fp;
        struct mount *mp;
        struct vnode *vp;
        cap_rights_t rights;
        int error;

        AUDIT_ARG_FD(fd);
        error = getvnode(td, fd, cap_rights_init(&rights, CAP_FSTATFS), &fp);
        if (error != 0)
                return (error);
        vp = fp->f_vnode;
        vn_lock(vp, LK_SHARED | LK_RETRY);
#ifdef AUDIT
        AUDIT_ARG_VNODE1(vp);
#endif
        mp = vp->v_mount;
        if (mp != NULL)
                vfs_ref(mp);
        VOP_UNLOCK(vp, 0);
        fdrop(fp, td);
        return (kern_do_statfs(td, mp, buf));
}

/*
 * Get statistics on all filesystems.
 */
#ifndef _SYS_SYSPROTO_H_
struct getfsstat_args {
        struct statfs *buf;
        long bufsize;
        int mode;
};
#endif
int
sys_getfsstat(struct thread *td, struct getfsstat_args *uap)
{
        size_t count;
        int error;

        if (uap->bufsize < 0 || uap->bufsize > SIZE_MAX)
                return (EINVAL);
        error = kern_getfsstat(td, &uap->buf, uap->bufsize, &count,
            UIO_USERSPACE, uap->mode);
        if (error == 0)
                td->td_retval[0] = count;
        return (error);
}

/*
 * If (bufsize > 0 && bufseg == UIO_SYSSPACE)
 *      The caller is responsible for freeing memory which will be allocated
 *      in '*buf'.
 */
int
kern_getfsstat(struct thread *td, struct statfs **buf, size_t bufsize,
    size_t *countp, enum uio_seg bufseg, int mode)
{
        struct mount *mp, *nmp;
        struct statfs *sfsp, *sp, *sptmp, *tofree;
        size_t count, maxcount;
        int error;

        switch (mode) {
        case MNT_WAIT:
        case MNT_NOWAIT:
                break;
        default:
                if (bufseg == UIO_SYSSPACE)
                        *buf = NULL;
                return (EINVAL);
        }
restart:
        maxcount = bufsize / sizeof(struct statfs);
        if (bufsize == 0) {
                sfsp = NULL;
                tofree = NULL;
        } else if (bufseg == UIO_USERSPACE) {
                sfsp = *buf;
                tofree = NULL;
        } else /* if (bufseg == UIO_SYSSPACE) */ {
                count = 0;
                mtx_lock(&mountlist_mtx);
                TAILQ_FOREACH(mp, &mountlist, mnt_list) {
                        count++;
                }
                mtx_unlock(&mountlist_mtx);
                if (maxcount > count)
                        maxcount = count;
                tofree = sfsp = *buf = malloc(maxcount * sizeof(struct statfs),
                    M_STATFS, M_WAITOK);
        }
        count = 0;
        mtx_lock(&mountlist_mtx);
        for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
                if (prison_canseemount(td->td_ucred, mp) != 0) {
                        nmp = TAILQ_NEXT(mp, mnt_list);
                        continue;
                }
#ifdef MAC
                if (mac_mount_check_stat(td->td_ucred, mp) != 0) {
                        nmp = TAILQ_NEXT(mp, mnt_list);
                        continue;
                }
#endif
                if (mode == MNT_WAIT) {
                        if (vfs_busy(mp, MBF_MNTLSTLOCK) != 0) {
                                /*
                                 * If vfs_busy() failed, and MBF_NOWAIT
                                 * wasn't passed, then the mp is gone.
                                 * Furthermore, because of MBF_MNTLSTLOCK,
                                 * the mountlist_mtx was dropped.  We have
                                 * no other choice than to start over.
                                 */
                                mtx_unlock(&mountlist_mtx);
                                free(tofree, M_STATFS);
                                goto restart;
                        }
                } else {
                        if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK) != 0) {
                                nmp = TAILQ_NEXT(mp, mnt_list);
                                continue;
                        }
                }
                if (sfsp != NULL && count < maxcount) {
                        sp = &mp->mnt_stat;
                        /*
                         * Set these in case the underlying filesystem
                         * fails to do so.
                         */
                        sp->f_version = STATFS_VERSION;
                        sp->f_namemax = NAME_MAX;
                        sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
                        /*
                         * If MNT_NOWAIT is specified, do not refresh
                         * the fsstat cache.
                         */
                        if (mode != MNT_NOWAIT) {
                                error = VFS_STATFS(mp, sp);
                                if (error != 0) {
                                        mtx_lock(&mountlist_mtx);
                                        nmp = TAILQ_NEXT(mp, mnt_list);
                                        vfs_unbusy(mp);
                                        continue;
                                }
                        }
                        if (priv_check(td, PRIV_VFS_GENERATION)) {
                                sptmp = malloc(sizeof(struct statfs), M_STATFS,
                                    M_WAITOK);
                                *sptmp = *sp;
                                sptmp->f_fsid.val[0] = sptmp->f_fsid.val[1] = 0;
                                prison_enforce_statfs(td->td_ucred, mp, sptmp);
                                sp = sptmp;
                        } else
                                sptmp = NULL;
                        if (bufseg == UIO_SYSSPACE) {
                                bcopy(sp, sfsp, sizeof(*sp));
                                free(sptmp, M_STATFS);
                        } else /* if (bufseg == UIO_USERSPACE) */ {
                                error = copyout(sp, sfsp, sizeof(*sp));
                                free(sptmp, M_STATFS);
                                if (error != 0) {
                                        vfs_unbusy(mp);
                                        return (error);
                                }
                        }
                        sfsp++;
                }
                count++;
                mtx_lock(&mountlist_mtx);
                nmp = TAILQ_NEXT(mp, mnt_list);
                vfs_unbusy(mp);
        }
        mtx_unlock(&mountlist_mtx);
        if (sfsp != NULL && count > maxcount)
                *countp = maxcount;
        else
                *countp = count;
        return (0);
}

#ifdef COMPAT_FREEBSD4
/*
 * Get old format filesystem statistics.
 */
static void freebsd4_cvtstatfs(struct statfs *, struct ostatfs *);

#ifndef _SYS_SYSPROTO_H_
struct freebsd4_statfs_args {
        char *path;
        struct ostatfs *buf;
};
#endif
int
freebsd4_statfs(struct thread *td, struct freebsd4_statfs_args *uap)
{
        struct ostatfs osb;
        struct statfs *sfp;
        int error;

        sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
        error = kern_statfs(td, uap->path, UIO_USERSPACE, sfp);
        if (error == 0) {
                freebsd4_cvtstatfs(sfp, &osb);
                error = copyout(&osb, uap->buf, sizeof(osb));
        }
        free(sfp, M_STATFS);
        return (error);
}

/*
 * Get filesystem statistics.
 */
#ifndef _SYS_SYSPROTO_H_
struct freebsd4_fstatfs_args {
        int fd;
        struct ostatfs *buf;
};
#endif
int
freebsd4_fstatfs(struct thread *td, struct freebsd4_fstatfs_args *uap)
{
        struct ostatfs osb;
        struct statfs *sfp;
        int error;

        sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
        error = kern_fstatfs(td, uap->fd, sfp);
        if (error == 0) {
                freebsd4_cvtstatfs(sfp, &osb);
                error = copyout(&osb, uap->buf, sizeof(osb));
        }
        free(sfp, M_STATFS);
        return (error);
}

/*
 * Get statistics on all filesystems.
 */
#ifndef _SYS_SYSPROTO_H_
struct freebsd4_getfsstat_args {
        struct ostatfs *buf;
        long bufsize;
        int mode;
};
#endif
int
freebsd4_getfsstat(struct thread *td, struct freebsd4_getfsstat_args *uap)
{
        struct statfs *buf, *sp;
        struct ostatfs osb;
        size_t count, size;
        int error;

        if (uap->bufsize < 0)
                return (EINVAL);
        count = uap->bufsize / sizeof(struct ostatfs);
        if (count > SIZE_MAX / sizeof(struct statfs))
                return (EINVAL);
        size = count * sizeof(struct statfs);
        error = kern_getfsstat(td, &buf, size, &count, UIO_SYSSPACE,
            uap->mode);
        if (error == 0)
                td->td_retval[0] = count;
        if (size != 0) {
                sp = buf;
                while (count != 0 && error == 0) {
                        freebsd4_cvtstatfs(sp, &osb);
                        error = copyout(&osb, uap->buf, sizeof(osb));
                        sp++;
                        uap->buf++;
                        count--;
                }
                free(buf, M_STATFS);
        }
        return (error);
}

/*
 * Implement fstatfs() for (NFS) file handles.
 */
#ifndef _SYS_SYSPROTO_H_
struct freebsd4_fhstatfs_args {
        struct fhandle *u_fhp;
        struct ostatfs *buf;
};
#endif
int
freebsd4_fhstatfs(struct thread *td, struct freebsd4_fhstatfs_args *uap)
{
        struct ostatfs osb;
        struct statfs *sfp;
        fhandle_t fh;
        int error;

        error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
        if (error != 0)
                return (error);
        sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
        error = kern_fhstatfs(td, fh, sfp);
        if (error == 0) {
                freebsd4_cvtstatfs(sfp, &osb);
                error = copyout(&osb, uap->buf, sizeof(osb));
        }
        free(sfp, M_STATFS);
        return (error);
}

/*
 * Convert a new format statfs structure to an old format statfs structure.
 */
static void
freebsd4_cvtstatfs(struct statfs *nsp, struct ostatfs *osp)
{

        statfs_scale_blocks(nsp, LONG_MAX);
        bzero(osp, sizeof(*osp));
        osp->f_bsize = nsp->f_bsize;
        osp->f_iosize = MIN(nsp->f_iosize, LONG_MAX);
        osp->f_blocks = nsp->f_blocks;
        osp->f_bfree = nsp->f_bfree;
        osp->f_bavail = nsp->f_bavail;
        osp->f_files = MIN(nsp->f_files, LONG_MAX);
        osp->f_ffree = MIN(nsp->f_ffree, LONG_MAX);
        osp->f_owner = nsp->f_owner;
        osp->f_type = nsp->f_type;
        osp->f_flags = nsp->f_flags;
        osp->f_syncwrites = MIN(nsp->f_syncwrites, LONG_MAX);
        osp->f_asyncwrites = MIN(nsp->f_asyncwrites, LONG_MAX);
        osp->f_syncreads = MIN(nsp->f_syncreads, LONG_MAX);
        osp->f_asyncreads = MIN(nsp->f_asyncreads, LONG_MAX);
        strlcpy(osp->f_fstypename, nsp->f_fstypename,
            MIN(MFSNAMELEN, OMFSNAMELEN));
        strlcpy(osp->f_mntonname, nsp->f_mntonname,
            MIN(MNAMELEN, OMNAMELEN));
        strlcpy(osp->f_mntfromname, nsp->f_mntfromname,
            MIN(MNAMELEN, OMNAMELEN));
        osp->f_fsid = nsp->f_fsid;
}
#endif /* COMPAT_FREEBSD4 */

#if defined(COMPAT_FREEBSD11)
/*
 * Get old format filesystem statistics.
 */
static void freebsd11_cvtstatfs(struct statfs *, struct freebsd11_statfs *);

int
freebsd11_statfs(struct thread *td, struct freebsd11_statfs_args *uap)
{
        struct freebsd11_statfs osb;
        struct statfs *sfp;
        int error;

        sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
        error = kern_statfs(td, uap->path, UIO_USERSPACE, sfp);
        if (error == 0) {
                freebsd11_cvtstatfs(sfp, &osb);
                error = copyout(&osb, uap->buf, sizeof(osb));
        }
        free(sfp, M_STATFS);
        return (error);
}

/*
 * Get filesystem statistics.
 */
int
freebsd11_fstatfs(struct thread *td, struct freebsd11_fstatfs_args *uap)
{
        struct freebsd11_statfs osb;
        struct statfs *sfp;
        int error;

        sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
        error = kern_fstatfs(td, uap->fd, sfp);
        if (error == 0) {
                freebsd11_cvtstatfs(sfp, &osb);
                error = copyout(&osb, uap->buf, sizeof(osb));
        }
        free(sfp, M_STATFS);
        return (error);
}

/*
 * Get statistics on all filesystems.
 */
int
freebsd11_getfsstat(struct thread *td, struct freebsd11_getfsstat_args *uap)
{
        struct freebsd11_statfs osb;
        struct statfs *buf, *sp;
        size_t count, size;
        int error;

        count = uap->bufsize / sizeof(struct ostatfs);
        size = count * sizeof(struct statfs);
        error = kern_getfsstat(td, &buf, size, &count, UIO_SYSSPACE,
            uap->mode);
        if (error == 0)
                td->td_retval[0] = count;
        if (size > 0) {
                sp = buf;
                while (count > 0 && error == 0) {
                        freebsd11_cvtstatfs(sp, &osb);
                        error = copyout(&osb, uap->buf, sizeof(osb));
                        sp++;
                        uap->buf++;
                        count--;
                }
                free(buf, M_STATFS);
        }
        return (error);
}

/*
 * Implement fstatfs() for (NFS) file handles.
 */
int
freebsd11_fhstatfs(struct thread *td, struct freebsd11_fhstatfs_args *uap)
{
        struct freebsd11_statfs osb;
        struct statfs *sfp;
        fhandle_t fh;
        int error;

        error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
        if (error)
                return (error);
        sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
        error = kern_fhstatfs(td, fh, sfp);
        if (error == 0) {
                freebsd11_cvtstatfs(sfp, &osb);
                error = copyout(&osb, uap->buf, sizeof(osb));
        }
        free(sfp, M_STATFS);
        return (error);
}

/*
 * Convert a new format statfs structure to an old format statfs structure.
 */
static void
freebsd11_cvtstatfs(struct statfs *nsp, struct freebsd11_statfs *osp)
{

        bzero(osp, sizeof(*osp));
        osp->f_version = FREEBSD11_STATFS_VERSION;
        osp->f_type = nsp->f_type;
        osp->f_flags = nsp->f_flags;
        osp->f_bsize = nsp->f_bsize;
        osp->f_iosize = nsp->f_iosize;
        osp->f_blocks = nsp->f_blocks;
        osp->f_bfree = nsp->f_bfree;
        osp->f_bavail = nsp->f_bavail;
        osp->f_files = nsp->f_files;
        osp->f_ffree = nsp->f_ffree;
        osp->f_syncwrites = nsp->f_syncwrites;
        osp->f_asyncwrites = nsp->f_asyncwrites;
        osp->f_syncreads = nsp->f_syncreads;
        osp->f_asyncreads = nsp->f_asyncreads;
        osp->f_namemax = nsp->f_namemax;
        osp->f_owner = nsp->f_owner;
        osp->f_fsid = nsp->f_fsid;
        strlcpy(osp->f_fstypename, nsp->f_fstypename,
            MIN(MFSNAMELEN, sizeof(osp->f_fstypename)));
        strlcpy(osp->f_mntonname, nsp->f_mntonname,
            MIN(MNAMELEN, sizeof(osp->f_mntonname)));
        strlcpy(osp->f_mntfromname, nsp->f_mntfromname,
            MIN(MNAMELEN, sizeof(osp->f_mntfromname)));
}
#endif /* COMPAT_FREEBSD11 */

/*
 * Change current working directory to a given file descriptor.
 */
#ifndef _SYS_SYSPROTO_H_
struct fchdir_args {
        int     fd;
};
#endif
int
sys_fchdir(struct thread *td, struct fchdir_args *uap)
{
        struct vnode *vp, *tdp;
        struct mount *mp;
        struct file *fp;
        cap_rights_t rights;
        int error;

        AUDIT_ARG_FD(uap->fd);
        error = getvnode(td, uap->fd, cap_rights_init(&rights, CAP_FCHDIR),
            &fp);
        if (error != 0)
                return (error);
        vp = fp->f_vnode;
        vrefact(vp);
        fdrop(fp, td);
        vn_lock(vp, LK_SHARED | LK_RETRY);
        AUDIT_ARG_VNODE1(vp);
        error = change_dir(vp, td);
        while (!error && (mp = vp->v_mountedhere) != NULL) {
                if (vfs_busy(mp, 0))
                        continue;
                error = VFS_ROOT(mp, LK_SHARED, &tdp);
                vfs_unbusy(mp);
                if (error != 0)
                        break;
                vput(vp);
                vp = tdp;
        }
        if (error != 0) {
                vput(vp);
                return (error);
        }
        VOP_UNLOCK(vp, 0);
        pwd_chdir(td, vp);
        return (0);
}

/*
 * Change current working directory (``.'').
 */
#ifndef _SYS_SYSPROTO_H_
struct chdir_args {
        char    *path;
};
#endif
int
sys_chdir(struct thread *td, struct chdir_args *uap)
{

        return (kern_chdir(td, uap->path, UIO_USERSPACE));
}

int
kern_chdir(struct thread *td, char *path, enum uio_seg pathseg)
{
        struct nameidata nd;
        int error;

        NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1,
            pathseg, path, td);
        if ((error = namei(&nd)) != 0)
                return (error);
        if ((error = change_dir(nd.ni_vp, td)) != 0) {
                vput(nd.ni_vp);
                NDFREE(&nd, NDF_ONLY_PNBUF);
                return (error);
        }
        VOP_UNLOCK(nd.ni_vp, 0);
        NDFREE(&nd, NDF_ONLY_PNBUF);
        pwd_chdir(td, nd.ni_vp);
        return (0);
}

/*
 * Change notion of root (``/'') directory.
 */
#ifndef _SYS_SYSPROTO_H_
struct chroot_args {
        char    *path;
};
#endif
int
sys_chroot(struct thread *td, struct chroot_args *uap)
{
        struct nameidata nd;
        int error;

        error = priv_check(td, PRIV_VFS_CHROOT);
        if (error != 0)
                return (error);
        NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1,
            UIO_USERSPACE, uap->path, td);
        error = namei(&nd);
        if (error != 0)
                goto error;
        error = change_dir(nd.ni_vp, td);
        if (error != 0)
                goto e_vunlock;
#ifdef MAC
        error = mac_vnode_check_chroot(td->td_ucred, nd.ni_vp);
        if (error != 0)
                goto e_vunlock;
#endif
        VOP_UNLOCK(nd.ni_vp, 0);
        error = pwd_chroot(td, nd.ni_vp);
        vrele(nd.ni_vp);
        NDFREE(&nd, NDF_ONLY_PNBUF);
        return (error);
e_vunlock:
        vput(nd.ni_vp);
error:
        NDFREE(&nd, NDF_ONLY_PNBUF);
        return (error);
}

/*
 * Common routine for chroot and chdir.  Callers must provide a locked vnode
 * instance.
 */
int
change_dir(struct vnode *vp, struct thread *td)
{
#ifdef MAC
        int error;
#endif

        ASSERT_VOP_LOCKED(vp, "change_dir(): vp not locked");
        if (vp->v_type != VDIR)
                return (ENOTDIR);
#ifdef MAC
        error = mac_vnode_check_chdir(td->td_ucred, vp);
        if (error != 0)
                return (error);
#endif
        return (VOP_ACCESS(vp, VEXEC, td->td_ucred, td));
}

static __inline void
flags_to_rights(int flags, cap_rights_t *rightsp)
{

        if (flags & O_EXEC) {
                cap_rights_set(rightsp, CAP_FEXECVE);
        } else {
                switch ((flags & O_ACCMODE)) {
                case O_RDONLY:
                        cap_rights_set(rightsp, CAP_READ);
                        break;
                case O_RDWR:
                        cap_rights_set(rightsp, CAP_READ);
                        /* FALLTHROUGH */
                case O_WRONLY:
                        cap_rights_set(rightsp, CAP_WRITE);
                        if (!(flags & (O_APPEND | O_TRUNC)))
                                cap_rights_set(rightsp, CAP_SEEK);
                        break;
                }
        }

        if (flags & O_CREAT)
                cap_rights_set(rightsp, CAP_CREATE);

        if (flags & O_TRUNC)
                cap_rights_set(rightsp, CAP_FTRUNCATE);

        if (flags & (O_SYNC | O_FSYNC))
                cap_rights_set(rightsp, CAP_FSYNC);

        if (flags & (O_EXLOCK | O_SHLOCK))
                cap_rights_set(rightsp, CAP_FLOCK);
}

/*
 * Check permissions, allocate an open file structure, and call the device
 * open routine if any.
 */
#ifndef _SYS_SYSPROTO_H_
struct open_args {
        char    *path;
        int     flags;
        int     mode;
};
#endif
int
sys_open(struct thread *td, struct open_args *uap)
{

        return (kern_openat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
            uap->flags, uap->mode));
}

#ifndef _SYS_SYSPROTO_H_
struct openat_args {
        int     fd;
        char    *path;
        int     flag;
        int     mode;
};
#endif
int
sys_openat(struct thread *td, struct openat_args *uap)
{

        AUDIT_ARG_FD(uap->fd);
        return (kern_openat(td, uap->fd, uap->path, UIO_USERSPACE, uap->flag,
            uap->mode));
}

int
kern_openat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
    int flags, int mode)
{
        struct proc *p = td->td_proc;
        struct filedesc *fdp = p->p_fd;
        struct file *fp;
        struct vnode *vp;
        struct nameidata nd;
        cap_rights_t rights;
        int cmode, error, indx;

        indx = -1;

        AUDIT_ARG_FFLAGS(flags);
        AUDIT_ARG_MODE(mode);
        cap_rights_init(&rights, CAP_LOOKUP);
        flags_to_rights(flags, &rights);
        /*
         * Only one of the O_EXEC, O_RDONLY, O_WRONLY and O_RDWR flags
         * may be specified.
         */
        if (flags & O_EXEC) {
                if (flags & O_ACCMODE)
                        return (EINVAL);
        } else if ((flags & O_ACCMODE) == O_ACCMODE) {
                return (EINVAL);
        } else {
                flags = FFLAGS(flags);
        }

        /*
         * Allocate a file structure. The descriptor to reference it
         * is allocated and set by finstall() below.
         */
        error = falloc_noinstall(td, &fp);
        if (error != 0)
                return (error);
        /*
         * An extra reference on `fp' has been held for us by
         * falloc_noinstall().
         */
        /* Set the flags early so the finit in devfs can pick them up. */
        fp->f_flag = flags & FMASK;
        cmode = ((mode & ~fdp->fd_cmask) & ALLPERMS) & ~S_ISTXT;
        NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path, fd,
            &rights, td);
        td->td_dupfd = -1;              /* XXX check for fdopen */
        error = vn_open(&nd, &flags, cmode, fp);
        if (error != 0) {
                /*
                 * If the vn_open replaced the method vector, something
                 * wonderous happened deep below and we just pass it up
                 * pretending we know what we do.
                 */
                if (error == ENXIO && fp->f_ops != &badfileops)
                        goto success;

                /*
                 * Handle special fdopen() case. bleh.
                 *
                 * Don't do this for relative (capability) lookups; we don't
                 * understand exactly what would happen, and we don't think
                 * that it ever should.
                 */
                if ((nd.ni_lcf & NI_LCF_STRICTRELATIVE) == 0 &&
                    (error == ENODEV || error == ENXIO) &&
                    td->td_dupfd >= 0) {
                        error = dupfdopen(td, fdp, td->td_dupfd, flags, error,
                            &indx);
                        if (error == 0)
                                goto success;
                }

                goto bad;
        }
        td->td_dupfd = 0;
        NDFREE(&nd, NDF_ONLY_PNBUF);
        vp = nd.ni_vp;

        /*
         * Store the vnode, for any f_type. Typically, the vnode use
         * count is decremented by direct call to vn_closefile() for
         * files that switched type in the cdevsw fdopen() method.
         */
        fp->f_vnode = vp;
        /*
         * If the file wasn't claimed by devfs bind it to the normal
         * vnode operations here.
         */
        if (fp->f_ops == &badfileops) {
                KASSERT(vp->v_type != VFIFO, ("Unexpected fifo."));
                fp->f_seqcount = 1;
                finit(fp, (flags & FMASK) | (fp->f_flag & FHASLOCK),
                    DTYPE_VNODE, vp, &vnops);
        }

        VOP_UNLOCK(vp, 0);
        if (flags & O_TRUNC) {
                error = fo_truncate(fp, 0, td->td_ucred, td);
                if (error != 0)
                        goto bad;
        }
success:
        /*
         * If we haven't already installed the FD (for dupfdopen), do so now.
         */
        if (indx == -1) {
                struct filecaps *fcaps;

#ifdef CAPABILITIES
                if ((nd.ni_lcf & NI_LCF_STRICTRELATIVE) != 0)
                        fcaps = &nd.ni_filecaps;
                else
#endif
                        fcaps = NULL;
                error = finstall(td, fp, &indx, flags, fcaps);
                /* On success finstall() consumes fcaps. */
                if (error != 0) {
                        filecaps_free(&nd.ni_filecaps);
                        goto bad;
                }
        } else {
                filecaps_free(&nd.ni_filecaps);
        }

        /*
         * Release our private reference, leaving the one associated with
         * the descriptor table intact.
         */
        fdrop(fp, td);
        td->td_retval[0] = indx;
        return (0);
bad:
        KASSERT(indx == -1, ("indx=%d, should be -1", indx));
        fdrop(fp, td);
        return (error);
}

#ifdef COMPAT_43
/*
 * Create a file.
 */
#ifndef _SYS_SYSPROTO_H_
struct ocreat_args {
        char    *path;
        int     mode;
};
#endif
int
ocreat(struct thread *td, struct ocreat_args *uap)
{

        return (kern_openat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
            O_WRONLY | O_CREAT | O_TRUNC, uap->mode));
}
#endif /* COMPAT_43 */

/*
 * Create a special file.
 */
#ifndef _SYS_SYSPROTO_H_
struct mknodat_args {
        int     fd;
        char    *path;
        mode_t  mode;
        dev_t   dev;
};
#endif
int
sys_mknodat(struct thread *td, struct mknodat_args *uap)
{

        return (kern_mknodat(td, uap->fd, uap->path, UIO_USERSPACE, uap->mode,
            uap->dev));
}

#if defined(COMPAT_FREEBSD11)
int
freebsd11_mknod(struct thread *td,
    struct freebsd11_mknod_args *uap)
{

        return (kern_mknodat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
            uap->mode, uap->dev));
}

int
freebsd11_mknodat(struct thread *td,
    struct freebsd11_mknodat_args *uap)
{

        return (kern_mknodat(td, uap->fd, uap->path, UIO_USERSPACE, uap->mode,
            uap->dev));
}
#endif /* COMPAT_FREEBSD11 */

int
kern_mknodat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
    int mode, dev_t dev)
{
        struct vnode *vp;
        struct mount *mp;
        struct vattr vattr;
        struct nameidata nd;
        cap_rights_t rights;
        int error, whiteout = 0;

        AUDIT_ARG_MODE(mode);
        AUDIT_ARG_DEV(dev);
        switch (mode & S_IFMT) {
        case S_IFCHR:
        case S_IFBLK:
                error = priv_check(td, PRIV_VFS_MKNOD_DEV);
                if (error == 0 && dev == VNOVAL)
                        error = EINVAL;
                break;
        case S_IFWHT:
                error = priv_check(td, PRIV_VFS_MKNOD_WHT);
                break;
        case S_IFIFO:
                if (dev == 0)
                        return (kern_mkfifoat(td, fd, path, pathseg, mode));
                /* FALLTHROUGH */
        default:
                error = EINVAL;
                break;
        }
        if (error != 0)
                return (error);
restart:
        bwillwrite();
        NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | SAVENAME | AUDITVNODE1 |
            NOCACHE, pathseg, path, fd, cap_rights_init(&rights, CAP_MKNODAT),
            td);
        if ((error = namei(&nd)) != 0)
                return (error);
        vp = nd.ni_vp;
        if (vp != NULL) {
                NDFREE(&nd, NDF_ONLY_PNBUF);
                if (vp == nd.ni_dvp)
                        vrele(nd.ni_dvp);
                else
                        vput(nd.ni_dvp);
                vrele(vp);
                return (EEXIST);
        } else {
                VATTR_NULL(&vattr);
                vattr.va_mode = (mode & ALLPERMS) &
                    ~td->td_proc->p_fd->fd_cmask;
                vattr.va_rdev = dev;
                whiteout = 0;

                switch (mode & S_IFMT) {
                case S_IFCHR:
                        vattr.va_type = VCHR;
                        break;
                case S_IFBLK:
                        vattr.va_type = VBLK;
                        break;
                case S_IFWHT:
                        whiteout = 1;
                        break;
                default:
                        panic("kern_mknod: invalid mode");
                }
        }
        if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
                NDFREE(&nd, NDF_ONLY_PNBUF);
                vput(nd.ni_dvp);
                if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
                        return (error);
                goto restart;
        }
#ifdef MAC
        if (error == 0 && !whiteout)
                error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp,
                    &nd.ni_cnd, &vattr);
#endif
        if (error == 0) {
                if (whiteout)
                        error = VOP_WHITEOUT(nd.ni_dvp, &nd.ni_cnd, CREATE);
                else {
                        error = VOP_MKNOD(nd.ni_dvp, &nd.ni_vp,
                                                &nd.ni_cnd, &vattr);
                        if (error == 0)
                                vput(nd.ni_vp);
                }
        }
        NDFREE(&nd, NDF_ONLY_PNBUF);
        vput(nd.ni_dvp);
        vn_finished_write(mp);
        return (error);
}

/*
 * Create a named pipe.
 */
#ifndef _SYS_SYSPROTO_H_
struct mkfifo_args {
        char    *path;
        int     mode;
};
#endif
int
sys_mkfifo(struct thread *td, struct mkfifo_args *uap)
{

        return (kern_mkfifoat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
            uap->mode));
}

#ifndef _SYS_SYSPROTO_H_
struct mkfifoat_args {
        int     fd;
        char    *path;
        mode_t  mode;
};
#endif
int
sys_mkfifoat(struct thread *td, struct mkfifoat_args *uap)
{

        return (kern_mkfifoat(td, uap->fd, uap->path, UIO_USERSPACE,
            uap->mode));
}

int
kern_mkfifoat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
    int mode)
{
        struct mount *mp;
        struct vattr vattr;
        struct nameidata nd;
        cap_rights_t rights;
        int error;

        AUDIT_ARG_MODE(mode);
restart:
        bwillwrite();
        NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | SAVENAME | AUDITVNODE1 |
            NOCACHE, pathseg, path, fd, cap_rights_init(&rights, CAP_MKFIFOAT),
            td);
        if ((error = namei(&nd)) != 0)
                return (error);
        if (nd.ni_vp != NULL) {
                NDFREE(&nd, NDF_ONLY_PNBUF);
                if (nd.ni_vp == nd.ni_dvp)
                        vrele(nd.ni_dvp);
                else
                        vput(nd.ni_dvp);
                vrele(nd.ni_vp);
                return (EEXIST);
        }
        if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
                NDFREE(&nd, NDF_ONLY_PNBUF);
                vput(nd.ni_dvp);
                if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
                        return (error);
                goto restart;
        }
        VATTR_NULL(&vattr);
        vattr.va_type = VFIFO;
        vattr.va_mode = (mode & ALLPERMS) & ~td->td_proc->p_fd->fd_cmask;
#ifdef MAC
        error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
            &vattr);
        if (error != 0)
                goto out;
#endif
        error = VOP_MKNOD(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
        if (error == 0)
                vput(nd.ni_vp);
#ifdef MAC
out:
#endif
        vput(nd.ni_dvp);
        vn_finished_write(mp);
        NDFREE(&nd, NDF_ONLY_PNBUF);
        return (error);
}

/*
 * Make a hard file link.
 */
#ifndef _SYS_SYSPROTO_H_
struct link_args {
        char    *path;
        char    *link;
};
#endif
int
sys_link(struct thread *td, struct link_args *uap)
{

        return (kern_linkat(td, AT_FDCWD, AT_FDCWD, uap->path, uap->link,
            UIO_USERSPACE, FOLLOW));
}

#ifndef _SYS_SYSPROTO_H_
struct linkat_args {
        int     fd1;
        char    *path1;
        int     fd2;
        char    *path2;
        int     flag;
};
#endif
int
sys_linkat(struct thread *td, struct linkat_args *uap)
{
        int flag;

        flag = uap->flag;
        if (flag & ~AT_SYMLINK_FOLLOW)
                return (EINVAL);

        return (kern_linkat(td, uap->fd1, uap->fd2, uap->path1, uap->path2,
            UIO_USERSPACE, (flag & AT_SYMLINK_FOLLOW) ? FOLLOW : NOFOLLOW));
}

int hardlink_check_uid = 0;
SYSCTL_INT(_security_bsd, OID_AUTO, hardlink_check_uid, CTLFLAG_RW,
    &hardlink_check_uid, 0,
    "Unprivileged processes cannot create hard links to files owned by other "
    "users");
static int hardlink_check_gid = 0;
SYSCTL_INT(_security_bsd, OID_AUTO, hardlink_check_gid, CTLFLAG_RW,
    &hardlink_check_gid, 0,
    "Unprivileged processes cannot create hard links to files owned by other "
    "groups");

static int
can_hardlink(struct vnode *vp, struct ucred *cred)
{
        struct vattr va;
        int error;

        if (!hardlink_check_uid && !hardlink_check_gid)
                return (0);

        error = VOP_GETATTR(vp, &va, cred);
        if (error != 0)
                return (error);

        if (hardlink_check_uid && cred->cr_uid != va.va_uid) {
                error = priv_check_cred(cred, PRIV_VFS_LINK, 0);
                if (error != 0)
                        return (error);
        }

        if (hardlink_check_gid && !groupmember(va.va_gid, cred)) {
                error = priv_check_cred(cred, PRIV_VFS_LINK, 0);
                if (error != 0)
                        return (error);
        }

        return (0);
}

int
kern_linkat(struct thread *td, int fd1, int fd2, char *path1, char *path2,
    enum uio_seg segflg, int follow)
{
        struct vnode *vp;
        struct mount *mp;
        struct nameidata nd;
        cap_rights_t rights;
        int error;

again:
        bwillwrite();
        NDINIT_ATRIGHTS(&nd, LOOKUP, follow | AUDITVNODE1, segflg, path1, fd1,
            cap_rights_init(&rights, CAP_LINKAT_SOURCE), td);

        if ((error = namei(&nd)) != 0)
                return (error);
        NDFREE(&nd, NDF_ONLY_PNBUF);
        vp = nd.ni_vp;
        if (vp->v_type == VDIR) {
                vrele(vp);
                return (EPERM);         /* POSIX */
        }
        NDINIT_ATRIGHTS(&nd, CREATE,
            LOCKPARENT | SAVENAME | AUDITVNODE2 | NOCACHE, segflg, path2, fd2,
            cap_rights_init(&rights, CAP_LINKAT_TARGET), td);
        if ((error = namei(&nd)) == 0) {
                if (nd.ni_vp != NULL) {
                        NDFREE(&nd, NDF_ONLY_PNBUF);
                        if (nd.ni_dvp == nd.ni_vp)
                                vrele(nd.ni_dvp);
                        else
                                vput(nd.ni_dvp);
                        vrele(nd.ni_vp);
                        vrele(vp);
                        return (EEXIST);
                } else if (nd.ni_dvp->v_mount != vp->v_mount) {
                        /*
                         * Cross-device link.  No need to recheck
                         * vp->v_type, since it cannot change, except
                         * to VBAD.
                         */
                        NDFREE(&nd, NDF_ONLY_PNBUF);
                        vput(nd.ni_dvp);
                        vrele(vp);
                        return (EXDEV);
                } else if ((error = vn_lock(vp, LK_EXCLUSIVE)) == 0) {
                        error = can_hardlink(vp, td->td_ucred);
#ifdef MAC
                        if (error == 0)
                                error = mac_vnode_check_link(td->td_ucred,
                                    nd.ni_dvp, vp, &nd.ni_cnd);
#endif
                        if (error != 0) {
                                vput(vp);
                                vput(nd.ni_dvp);
                                NDFREE(&nd, NDF_ONLY_PNBUF);
                                return (error);
                        }
                        error = vn_start_write(vp, &mp, V_NOWAIT);
                        if (error != 0) {
                                vput(vp);
                                vput(nd.ni_dvp);
                                NDFREE(&nd, NDF_ONLY_PNBUF);
                                error = vn_start_write(NULL, &mp,
                                    V_XSLEEP | PCATCH);
                                if (error != 0)
                                        return (error);
                                goto again;
                        }
                        error = VOP_LINK(nd.ni_dvp, vp, &nd.ni_cnd);
                        VOP_UNLOCK(vp, 0);
                        vput(nd.ni_dvp);
                        vn_finished_write(mp);
                        NDFREE(&nd, NDF_ONLY_PNBUF);
                } else {
                        vput(nd.ni_dvp);
                        NDFREE(&nd, NDF_ONLY_PNBUF);
                        vrele(vp);
                        goto again;
                }
        }
        vrele(vp);
        return (error);
}

/*
 * Make a symbolic link.
 */
#ifndef _SYS_SYSPROTO_H_
struct symlink_args {
        char    *path;
        char    *link;
};
#endif
int
sys_symlink(struct thread *td, struct symlink_args *uap)
{

        return (kern_symlinkat(td, uap->path, AT_FDCWD, uap->link,
            UIO_USERSPACE));
}

#ifndef _SYS_SYSPROTO_H_
struct symlinkat_args {
        char    *path;
        int     fd;
        char    *path2;
};
#endif
int
sys_symlinkat(struct thread *td, struct symlinkat_args *uap)
{

        return (kern_symlinkat(td, uap->path1, uap->fd, uap->path2,
            UIO_USERSPACE));
}

int
kern_symlinkat(struct thread *td, char *path1, int fd, char *path2,
    enum uio_seg segflg)
{
        struct mount *mp;
        struct vattr vattr;
        char *syspath;
        struct nameidata nd;
        int error;
        cap_rights_t rights;

        if (segflg == UIO_SYSSPACE) {
                syspath = path1;
        } else {
                syspath = uma_zalloc(namei_zone, M_WAITOK);
                if ((error = copyinstr(path1, syspath, MAXPATHLEN, NULL)) != 0)
                        goto out;
        }
        AUDIT_ARG_TEXT(syspath);
restart:
        bwillwrite();
        NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | SAVENAME | AUDITVNODE1 |
            NOCACHE, segflg, path2, fd, cap_rights_init(&rights, CAP_SYMLINKAT),
            td);
        if ((error = namei(&nd)) != 0)
                goto out;
        if (nd.ni_vp) {
                NDFREE(&nd, NDF_ONLY_PNBUF);
                if (nd.ni_vp == nd.ni_dvp)
                        vrele(nd.ni_dvp);
                else
                        vput(nd.ni_dvp);
                vrele(nd.ni_vp);
                error = EEXIST;
                goto out;
        }
        if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
                NDFREE(&nd, NDF_ONLY_PNBUF);
                vput(nd.ni_dvp);
                if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
                        goto out;
                goto restart;
        }
        VATTR_NULL(&vattr);
        vattr.va_mode = ACCESSPERMS &~ td->td_proc->p_fd->fd_cmask;
#ifdef MAC
        vattr.va_type = VLNK;
        error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
            &vattr);
        if (error != 0)
                goto out2;
#endif
        error = VOP_SYMLINK(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr, syspath);
        if (error == 0)
                vput(nd.ni_vp);
#ifdef MAC
out2:
#endif
        NDFREE(&nd, NDF_ONLY_PNBUF);
        vput(nd.ni_dvp);
        vn_finished_write(mp);
out:
        if (segflg != UIO_SYSSPACE)
                uma_zfree(namei_zone, syspath);
        return (error);
}

/*
 * Delete a whiteout from the filesystem.
 */
#ifndef _SYS_SYSPROTO_H_
struct undelete_args {
        char *path;
};
#endif
int
sys_undelete(struct thread *td, struct undelete_args *uap)
{
        struct mount *mp;
        struct nameidata nd;
        int error;

restart:
        bwillwrite();
        NDINIT(&nd, DELETE, LOCKPARENT | DOWHITEOUT | AUDITVNODE1,
            UIO_USERSPACE, uap->path, td);
        error = namei(&nd);
        if (error != 0)
                return (error);

        if (nd.ni_vp != NULLVP || !(nd.ni_cnd.cn_flags & ISWHITEOUT)) {
                NDFREE(&nd, NDF_ONLY_PNBUF);
                if (nd.ni_vp == nd.ni_dvp)
                        vrele(nd.ni_dvp);
                else
                        vput(nd.ni_dvp);
                if (nd.ni_vp)
                        vrele(nd.ni_vp);
                return (EEXIST);
        }
        if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
                NDFREE(&nd, NDF_ONLY_PNBUF);
                vput(nd.ni_dvp);
                if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
                        return (error);
                goto restart;
        }
        error = VOP_WHITEOUT(nd.ni_dvp, &nd.ni_cnd, DELETE);
        NDFREE(&nd, NDF_ONLY_PNBUF);
        vput(nd.ni_dvp);
        vn_finished_write(mp);
        return (error);
}

/*
 * Delete a name from the filesystem.
 */
#ifndef _SYS_SYSPROTO_H_
struct unlink_args {
        char    *path;
};
#endif
int
sys_unlink(struct thread *td, struct unlink_args *uap)
{

        return (kern_unlinkat(td, AT_FDCWD, uap->path, UIO_USERSPACE, 0));
}

#ifndef _SYS_SYSPROTO_H_
struct unlinkat_args {
        int     fd;
        char    *path;
        int     flag;
};
#endif
int
sys_unlinkat(struct thread *td, struct unlinkat_args *uap)
{
        int flag = uap->flag;
        int fd = uap->fd;
        char *path = uap->path;

        if (flag & ~AT_REMOVEDIR)
                return (EINVAL);

        if (flag & AT_REMOVEDIR)
                return (kern_rmdirat(td, fd, path, UIO_USERSPACE));
        else
                return (kern_unlinkat(td, fd, path, UIO_USERSPACE, 0));
}

int
kern_unlinkat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
    ino_t oldinum)
{
        struct mount *mp;
        struct vnode *vp;
        struct nameidata nd;
        struct stat sb;
        cap_rights_t rights;
        int error;

restart:
        bwillwrite();
        NDINIT_ATRIGHTS(&nd, DELETE, LOCKPARENT | LOCKLEAF | AUDITVNODE1,
            pathseg, path, fd, cap_rights_init(&rights, CAP_UNLINKAT), td);
        if ((error = namei(&nd)) != 0)
                return (error == EINVAL ? EPERM : error);
        vp = nd.ni_vp;
        if (vp->v_type == VDIR && oldinum == 0) {
                error = EPERM;          /* POSIX */
        } else if (oldinum != 0 &&
                  ((error = vn_stat(vp, &sb, td->td_ucred, NOCRED, td)) == 0) &&
                  sb.st_ino != oldinum) {
                        error = EIDRM;  /* Identifier removed */
        } else {
                /*
                 * The root of a mounted filesystem cannot be deleted.
                 *
                 * XXX: can this only be a VDIR case?
                 */
                if (vp->v_vflag & VV_ROOT)
                        error = EBUSY;
        }
        if (error == 0) {
                if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
                        NDFREE(&nd, NDF_ONLY_PNBUF);
                        vput(nd.ni_dvp);
                        if (vp == nd.ni_dvp)
                                vrele(vp);
                        else
                                vput(vp);
                        if ((error = vn_start_write(NULL, &mp,
                            V_XSLEEP | PCATCH)) != 0)
                                return (error);
                        goto restart;
                }
#ifdef MAC
                error = mac_vnode_check_unlink(td->td_ucred, nd.ni_dvp, vp,
                    &nd.ni_cnd);
                if (error != 0)
                        goto out;
#endif
                vfs_notify_upper(vp, VFS_NOTIFY_UPPER_UNLINK);
                error = VOP_REMOVE(nd.ni_dvp, vp, &nd.ni_cnd);
#ifdef MAC
out:
#endif
                vn_finished_write(mp);
        }
        NDFREE(&nd, NDF_ONLY_PNBUF);
        vput(nd.ni_dvp);
        if (vp == nd.ni_dvp)
                vrele(vp);
        else
                vput(vp);
        return (error);
}

/*
 * Reposition read/write file offset.
 */
#ifndef _SYS_SYSPROTO_H_
struct lseek_args {
        int     fd;
        int     pad;
        off_t   offset;
        int     whence;
};
#endif
int
sys_lseek(struct thread *td, struct lseek_args *uap)
{

        return (kern_lseek(td, uap->fd, uap->offset, uap->whence));
}

int
kern_lseek(struct thread *td, int fd, off_t offset, int whence)
{
        struct file *fp;
        cap_rights_t rights;
        int error;

        AUDIT_ARG_FD(fd);
        error = fget(td, fd, cap_rights_init(&rights, CAP_SEEK), &fp);
        if (error != 0)
                return (error);
        error = (fp->f_ops->fo_flags & DFLAG_SEEKABLE) != 0 ?
            fo_seek(fp, offset, whence, td) : ESPIPE;
        fdrop(fp, td);
        return (error);
}

#if defined(COMPAT_43)
/*
 * Reposition read/write file offset.
 */
#ifndef _SYS_SYSPROTO_H_
struct olseek_args {
        int     fd;
        long    offset;
        int     whence;
};
#endif
int
olseek(struct thread *td, struct olseek_args *uap)
{

        return (kern_lseek(td, uap->fd, uap->offset, uap->whence));
}
#endif /* COMPAT_43 */

#if defined(COMPAT_FREEBSD6)
/* Version with the 'pad' argument */
int
freebsd6_lseek(struct thread *td, struct freebsd6_lseek_args *uap)
{

        return (kern_lseek(td, uap->fd, uap->offset, uap->whence));
}
#endif

/*
 * Check access permissions using passed credentials.
 */
static int
vn_access(struct vnode *vp, int user_flags, struct ucred *cred,
     struct thread *td)
{
        accmode_t accmode;
        int error;

        /* Flags == 0 means only check for existence. */
        if (user_flags == 0)
                return (0);

        accmode = 0;
        if (user_flags & R_OK)
                accmode |= VREAD;
        if (user_flags & W_OK)
                accmode |= VWRITE;
        if (user_flags & X_OK)
                accmode |= VEXEC;
#ifdef MAC
        error = mac_vnode_check_access(cred, vp, accmode);
        if (error != 0)
                return (error);
#endif
        if ((accmode & VWRITE) == 0 || (error = vn_writechk(vp)) == 0)
                error = VOP_ACCESS(vp, accmode, cred, td);
        return (error);
}

/*
 * Check access permissions using "real" credentials.
 */
#ifndef _SYS_SYSPROTO_H_
struct access_args {
        char    *path;
        int     amode;
};
#endif
int
sys_access(struct thread *td, struct access_args *uap)
{

        return (kern_accessat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
            0, uap->amode));
}

#ifndef _SYS_SYSPROTO_H_
struct faccessat_args {
        int     dirfd;
        char    *path;
        int     amode;
        int     flag;
}
#endif
int
sys_faccessat(struct thread *td, struct faccessat_args *uap)
{

        return (kern_accessat(td, uap->fd, uap->path, UIO_USERSPACE, uap->flag,
            uap->amode));
}

int
kern_accessat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
    int flag, int amode)
{
        struct ucred *cred, *usecred;
        struct vnode *vp;
        struct nameidata nd;
        cap_rights_t rights;
        int error;

        if (flag & ~AT_EACCESS)
                return (EINVAL);
        if (amode != F_OK && (amode & ~(R_OK | W_OK | X_OK)) != 0)
                return (EINVAL);

        /*
         * Create and modify a temporary credential instead of one that
         * is potentially shared (if we need one).
         */
        cred = td->td_ucred;
        if ((flag & AT_EACCESS) == 0 &&
            ((cred->cr_uid != cred->cr_ruid ||
            cred->cr_rgid != cred->cr_groups[0]))) {
                usecred = crdup(cred);
                usecred->cr_uid = cred->cr_ruid;
                usecred->cr_groups[0] = cred->cr_rgid;
                td->td_ucred = usecred;
        } else
                usecred = cred;
        AUDIT_ARG_VALUE(amode);
        NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF |
            AUDITVNODE1, pathseg, path, fd, cap_rights_init(&rights, CAP_FSTAT),
            td);
        if ((error = namei(&nd)) != 0)
                goto out;
        vp = nd.ni_vp;

        error = vn_access(vp, amode, usecred, td);
        NDFREE(&nd, NDF_ONLY_PNBUF);
        vput(vp);
out:
        if (usecred != cred) {
                td->td_ucred = cred;
                crfree(usecred);
        }
        return (error);
}

/*
 * Check access permissions using "effective" credentials.
 */
#ifndef _SYS_SYSPROTO_H_
struct eaccess_args {
        char    *path;
        int     amode;
};
#endif
int
sys_eaccess(struct thread *td, struct eaccess_args *uap)
{

        return (kern_accessat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
            AT_EACCESS, uap->amode));
}

#if defined(COMPAT_43)
/*
 * Get file status; this version follows links.
 */
#ifndef _SYS_SYSPROTO_H_
struct ostat_args {
        char    *path;
        struct ostat *ub;
};
#endif
int
ostat(struct thread *td, struct ostat_args *uap)
{
        struct stat sb;
        struct ostat osb;
        int error;

        error = kern_statat(td, 0, AT_FDCWD, uap->path, UIO_USERSPACE,
            &sb, NULL);
        if (error != 0)
                return (error);
        cvtstat(&sb, &osb);
        return (copyout(&osb, uap->ub, sizeof (osb)));
}

/*
 * Get file status; this version does not follow links.
 */
#ifndef _SYS_SYSPROTO_H_
struct olstat_args {
        char    *path;
        struct ostat *ub;
};
#endif
int
olstat(struct thread *td, struct olstat_args *uap)
{
        struct stat sb;
        struct ostat osb;
        int error;

        error = kern_statat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->path,
            UIO_USERSPACE, &sb, NULL);
        if (error != 0)
                return (error);
        cvtstat(&sb, &osb);
        return (copyout(&osb, uap->ub, sizeof (osb)));
}

/*
 * Convert from an old to a new stat structure.
 */
void
cvtstat(struct stat *st, struct ostat *ost)
{

        bzero(ost, sizeof(*ost));
        ost->st_dev = st->st_dev;
        ost->st_ino = st->st_ino;
        ost->st_mode = st->st_mode;
        ost->st_nlink = st->st_nlink;
        ost->st_uid = st->st_uid;
        ost->st_gid = st->st_gid;
        ost->st_rdev = st->st_rdev;
        if (st->st_size < (quad_t)1 << 32)
                ost->st_size = st->st_size;
        else
                ost->st_size = -2;
        ost->st_atim = st->st_atim;
        ost->st_mtim = st->st_mtim;
        ost->st_ctim = st->st_ctim;
        ost->st_blksize = st->st_blksize;
        ost->st_blocks = st->st_blocks;
        ost->st_flags = st->st_flags;
        ost->st_gen = st->st_gen;
}
#endif /* COMPAT_43 */

#if defined(COMPAT_43) || defined(COMPAT_FREEBSD11)
int ino64_trunc_error;
SYSCTL_INT(_vfs, OID_AUTO, ino64_trunc_error, CTLFLAG_RW,
    &ino64_trunc_error, 0,
    "Error on truncation of inode number, device id or link count");
int
freebsd11_cvtstat(struct stat *st, struct freebsd11_stat *ost)
{

        ost->st_dev = st->st_dev;
        ost->st_ino = st->st_ino;
        if (ost->st_ino != st->st_ino) {
                switch (ino64_trunc_error) {
                default:
                case 0:
                        break;
                case 1:
                        return (EOVERFLOW);
                case 2:
                        ost->st_ino = UINT32_MAX;
                        break;
                }
        }
        ost->st_mode = st->st_mode;
        ost->st_nlink = st->st_nlink;
        if (ost->st_nlink != st->st_nlink) {
                switch (ino64_trunc_error) {
                default:
                case 0:
                        break;
                case 1:
                        return (EOVERFLOW);
                case 2:
                        ost->st_nlink = UINT16_MAX;
                        break;
                }
        }
        ost->st_uid = st->st_uid;
        ost->st_gid = st->st_gid;
        ost->st_rdev = st->st_rdev;
        ost->st_atim = st->st_atim;
        ost->st_mtim = st->st_mtim;
        ost->st_ctim = st->st_ctim;
        ost->st_size = st->st_size;
        ost->st_blocks = st->st_blocks;
        ost->st_blksize = st->st_blksize;
        ost->st_flags = st->st_flags;
        ost->st_gen = st->st_gen;
        ost->st_lspare = 0;
        ost->st_birthtim = st->st_birthtim;
        bzero((char *)&ost->st_birthtim + sizeof(ost->st_birthtim),
            sizeof(*ost) - offsetof(struct freebsd11_stat,
            st_birthtim) - sizeof(ost->st_birthtim));
        return (0);
}

int
freebsd11_stat(struct thread *td, struct freebsd11_stat_args* uap)
{
        struct stat sb;
        struct freebsd11_stat osb;
        int error;

        error = kern_statat(td, 0, AT_FDCWD, uap->path, UIO_USERSPACE,
            &sb, NULL);
        if (error != 0)
                return (error);
        error = freebsd11_cvtstat(&sb, &osb);
        if (error == 0)
                error = copyout(&osb, uap->ub, sizeof(osb));
        return (error);
}

int
freebsd11_lstat(struct thread *td, struct freebsd11_lstat_args* uap)
{
        struct stat sb;
        struct freebsd11_stat osb;
        int error;

        error = kern_statat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->path,
            UIO_USERSPACE, &sb, NULL);
        if (error != 0)
                return (error);
        error = freebsd11_cvtstat(&sb, &osb);
        if (error == 0)
                error = copyout(&osb, uap->ub, sizeof(osb));
        return (error);
}

int
freebsd11_fhstat(struct thread *td, struct freebsd11_fhstat_args* uap)
{
        struct fhandle fh;
        struct stat sb;
        struct freebsd11_stat osb;
        int error;

        error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
        if (error != 0)
                return (error);
        error = kern_fhstat(td, fh, &sb);
        if (error != 0)
                return (error);
        error = freebsd11_cvtstat(&sb, &osb);
        if (error == 0)
                error = copyout(&osb, uap->sb, sizeof(osb));
        return (error);
}

int
freebsd11_fstatat(struct thread *td, struct freebsd11_fstatat_args* uap)
{
        struct stat sb;
        struct freebsd11_stat osb;
        int error;

        error = kern_statat(td, uap->flag, uap->fd, uap->path,
            UIO_USERSPACE, &sb, NULL);
        if (error != 0)
                return (error);
        error = freebsd11_cvtstat(&sb, &osb);
        if (error == 0)
                error = copyout(&osb, uap->buf, sizeof(osb));
        return (error);
}
#endif  /* COMPAT_FREEBSD11 */

/*
 * Get file status
 */
#ifndef _SYS_SYSPROTO_H_
struct fstatat_args {
        int     fd;
        char    *path;
        struct stat     *buf;
        int     flag;
}
#endif
int
sys_fstatat(struct thread *td, struct fstatat_args *uap)
{
        struct stat sb;
        int error;

        error = kern_statat(td, uap->flag, uap->fd, uap->path,
            UIO_USERSPACE, &sb, NULL);
        if (error == 0)
                error = copyout(&sb, uap->buf, sizeof (sb));
        return (error);
}

int
kern_statat(struct thread *td, int flag, int fd, char *path,
    enum uio_seg pathseg, struct stat *sbp,
    void (*hook)(struct vnode *vp, struct stat *sbp))
{
        struct nameidata nd;
        struct stat sb;
        cap_rights_t rights;
        int error;

        if (flag & ~AT_SYMLINK_NOFOLLOW)
                return (EINVAL);

        NDINIT_ATRIGHTS(&nd, LOOKUP, ((flag & AT_SYMLINK_NOFOLLOW) ? NOFOLLOW :
            FOLLOW) | LOCKSHARED | LOCKLEAF | AUDITVNODE1, pathseg, path, fd,
            cap_rights_init(&rights, CAP_FSTAT), td);

        if ((error = namei(&nd)) != 0)
                return (error);
        error = vn_stat(nd.ni_vp, &sb, td->td_ucred, NOCRED, td);
        if (error == 0) {
                SDT_PROBE2(vfs, , stat, mode, path, sb.st_mode);
                if (S_ISREG(sb.st_mode))
                        SDT_PROBE2(vfs, , stat, reg, path, pathseg);
                if (__predict_false(hook != NULL))
                        hook(nd.ni_vp, &sb);
        }
        NDFREE(&nd, NDF_ONLY_PNBUF);
        vput(nd.ni_vp);
        if (error != 0)
                return (error);
#ifdef __STAT_TIME_T_EXT
        sb.st_atim_ext = 0;
        sb.st_mtim_ext = 0;
        sb.st_ctim_ext = 0;
        sb.st_btim_ext = 0;
#endif
        *sbp = sb;
#ifdef KTRACE
        if (KTRPOINT(td, KTR_STRUCT))
                ktrstat(&sb);
#endif
        return (0);
}

#if defined(COMPAT_FREEBSD11)
/*
 * Implementation of the NetBSD [l]stat() functions.
 */
void
freebsd11_cvtnstat(struct stat *sb, struct nstat *nsb)
{

        bzero(nsb, sizeof(*nsb));
        nsb->st_dev = sb->st_dev;
        nsb->st_ino = sb->st_ino;
        nsb->st_mode = sb->st_mode;
        nsb->st_nlink = sb->st_nlink;
        nsb->st_uid = sb->st_uid;
        nsb->st_gid = sb->st_gid;
        nsb->st_rdev = sb->st_rdev;
        nsb->st_atim = sb->st_atim;
        nsb->st_mtim = sb->st_mtim;
        nsb->st_ctim = sb->st_ctim;
        nsb->st_size = sb->st_size;
        nsb->st_blocks = sb->st_blocks;
        nsb->st_blksize = sb->st_blksize;
        nsb->st_flags = sb->st_flags;
        nsb->st_gen = sb->st_gen;
        nsb->st_birthtim = sb->st_birthtim;
}

#ifndef _SYS_SYSPROTO_H_
struct freebsd11_nstat_args {
        char    *path;
        struct nstat *ub;
};
#endif
int
freebsd11_nstat(struct thread *td, struct freebsd11_nstat_args *uap)
{
        struct stat sb;
        struct nstat nsb;
        int error;

        error = kern_statat(td, 0, AT_FDCWD, uap->path, UIO_USERSPACE,
            &sb, NULL);
        if (error != 0)
                return (error);
        freebsd11_cvtnstat(&sb, &nsb);
        return (copyout(&nsb, uap->ub, sizeof (nsb)));
}

/*
 * NetBSD lstat.  Get file status; this version does not follow links.
 */
#ifndef _SYS_SYSPROTO_H_
struct freebsd11_nlstat_args {
        char    *path;
        struct nstat *ub;
};
#endif
int
freebsd11_nlstat(struct thread *td, struct freebsd11_nlstat_args *uap)
{
        struct stat sb;
        struct nstat nsb;
        int error;

        error = kern_statat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->path,
            UIO_USERSPACE, &sb, NULL);
        if (error != 0)
                return (error);
        freebsd11_cvtnstat(&sb, &nsb);
        return (copyout(&nsb, uap->ub, sizeof (nsb)));
}
#endif /* COMPAT_FREEBSD11 */

/*
 * Get configurable pathname variables.
 */
#ifndef _SYS_SYSPROTO_H_
struct pathconf_args {
        char    *path;
        int     name;
};
#endif
int
sys_pathconf(struct thread *td, struct pathconf_args *uap)
{
        long value;
        int error;

        error = kern_pathconf(td, uap->path, UIO_USERSPACE, uap->name, FOLLOW,
            &value);
        if (error == 0)
                td->td_retval[0] = value;
        return (error);
}

#ifndef _SYS_SYSPROTO_H_
struct lpathconf_args {
        char    *path;
        int     name;
};
#endif
int
sys_lpathconf(struct thread *td, struct lpathconf_args *uap)
{
        long value;
        int error;

        error = kern_pathconf(td, uap->path, UIO_USERSPACE, uap->name,
            NOFOLLOW, &value);
        if (error == 0)
                td->td_retval[0] = value;
        return (error);
}

int
kern_pathconf(struct thread *td, char *path, enum uio_seg pathseg, int name,
    u_long flags, long *valuep)
{
        struct nameidata nd;
        int error;

        NDINIT(&nd, LOOKUP, LOCKSHARED | LOCKLEAF | AUDITVNODE1 | flags,
            pathseg, path, td);
        if ((error = namei(&nd)) != 0)
                return (error);
        NDFREE(&nd, NDF_ONLY_PNBUF);

        error = VOP_PATHCONF(nd.ni_vp, name, valuep);
        vput(nd.ni_vp);
        return (error);
}

/*
 * Return target name of a symbolic link.
 */
#ifndef _SYS_SYSPROTO_H_
struct readlink_args {
        char    *path;
        char    *buf;
        size_t  count;
};
#endif
int
sys_readlink(struct thread *td, struct readlink_args *uap)
{

        return (kern_readlinkat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
            uap->buf, UIO_USERSPACE, uap->count));
}
#ifndef _SYS_SYSPROTO_H_
struct readlinkat_args {
        int     fd;
        char    *path;
        char    *buf;
        size_t  bufsize;
};
#endif
int
sys_readlinkat(struct thread *td, struct readlinkat_args *uap)
{

        return (kern_readlinkat(td, uap->fd, uap->path, UIO_USERSPACE,
            uap->buf, UIO_USERSPACE, uap->bufsize));
}

int
kern_readlinkat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
    char *buf, enum uio_seg bufseg, size_t count)
{
        struct vnode *vp;
        struct iovec aiov;
        struct uio auio;
        struct nameidata nd;
        int error;

        if (count > IOSIZE_MAX)
                return (EINVAL);

        NDINIT_AT(&nd, LOOKUP, NOFOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1,
            pathseg, path, fd, td);

        if ((error = namei(&nd)) != 0)
                return (error);
        NDFREE(&nd, NDF_ONLY_PNBUF);
        vp = nd.ni_vp;
#ifdef MAC
        error = mac_vnode_check_readlink(td->td_ucred, vp);
        if (error != 0) {
                vput(vp);
                return (error);
        }
#endif
        if (vp->v_type != VLNK && (vp->v_vflag & VV_READLINK) == 0)
                error = EINVAL;
        else {
                aiov.iov_base = buf;
                aiov.iov_len = count;
                auio.uio_iov = &aiov;
                auio.uio_iovcnt = 1;
                auio.uio_offset = 0;
                auio.uio_rw = UIO_READ;
                auio.uio_segflg = bufseg;
                auio.uio_td = td;
                auio.uio_resid = count;
                error = VOP_READLINK(vp, &auio, td->td_ucred);
                td->td_retval[0] = count - auio.uio_resid;
        }
        vput(vp);
        return (error);
}

/*
 * Common implementation code for chflags() and fchflags().
 */
static int
setfflags(struct thread *td, struct vnode *vp, u_long flags)
{
        struct mount *mp;
        struct vattr vattr;
        int error;

        /* We can't support the value matching VNOVAL. */
        if (flags == VNOVAL)
                return (EOPNOTSUPP);

        /*
         * Prevent non-root users from setting flags on devices.  When
         * a device is reused, users can retain ownership of the device
         * if they are allowed to set flags and programs assume that
         * chown can't fail when done as root.
         */
        if (vp->v_type == VCHR || vp->v_type == VBLK) {
                error = priv_check(td, PRIV_VFS_CHFLAGS_DEV);
                if (error != 0)
                        return (error);
        }

        if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
                return (error);
        VATTR_NULL(&vattr);
        vattr.va_flags = flags;
        vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
#ifdef MAC
        error = mac_vnode_check_setflags(td->td_ucred, vp, vattr.va_flags);
        if (error == 0)
#endif
                error = VOP_SETATTR(vp, &vattr, td->td_ucred);
        VOP_UNLOCK(vp, 0);
        vn_finished_write(mp);
        return (error);
}

/*
 * Change flags of a file given a path name.
 */
#ifndef _SYS_SYSPROTO_H_
struct chflags_args {
        const char *path;
        u_long  flags;
};
#endif
int
sys_chflags(struct thread *td, struct chflags_args *uap)
{

        return (kern_chflagsat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
            uap->flags, 0));
}

#ifndef _SYS_SYSPROTO_H_
struct chflagsat_args {
        int     fd;
        const char *path;
        u_long  flags;
        int     atflag;
}
#endif
int
sys_chflagsat(struct thread *td, struct chflagsat_args *uap)
{
        int fd = uap->fd;
        const char *path = uap->path;
        u_long flags = uap->flags;
        int atflag = uap->atflag;

        if (atflag & ~AT_SYMLINK_NOFOLLOW)
                return (EINVAL);

        return (kern_chflagsat(td, fd, path, UIO_USERSPACE, flags, atflag));
}

/*
 * Same as chflags() but doesn't follow symlinks.
 */
#ifndef _SYS_SYSPROTO_H_
struct lchflags_args {
        const char *path;
        u_long flags;
};
#endif
int
sys_lchflags(struct thread *td, struct lchflags_args *uap)
{

        return (kern_chflagsat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
            uap->flags, AT_SYMLINK_NOFOLLOW));
}

static int
kern_chflagsat(struct thread *td, int fd, const char *path,
    enum uio_seg pathseg, u_long flags, int atflag)
{
        struct nameidata nd;
        cap_rights_t rights;
        int error, follow;

        AUDIT_ARG_FFLAGS(flags);
        follow = (atflag & AT_SYMLINK_NOFOLLOW) ? NOFOLLOW : FOLLOW;
        NDINIT_ATRIGHTS(&nd, LOOKUP, follow | AUDITVNODE1, pathseg, path, fd,
            cap_rights_init(&rights, CAP_FCHFLAGS), td);
        if ((error = namei(&nd)) != 0)
                return (error);
        NDFREE(&nd, NDF_ONLY_PNBUF);
        error = setfflags(td, nd.ni_vp, flags);
        vrele(nd.ni_vp);
        return (error);
}

/*
 * Change flags of a file given a file descriptor.
 */
#ifndef _SYS_SYSPROTO_H_
struct fchflags_args {
        int     fd;
        u_long  flags;
};
#endif
int
sys_fchflags(struct thread *td, struct fchflags_args *uap)
{
        struct file *fp;
        cap_rights_t rights;
        int error;

        AUDIT_ARG_FD(uap->fd);
        AUDIT_ARG_FFLAGS(uap->flags);
        error = getvnode(td, uap->fd, cap_rights_init(&rights, CAP_FCHFLAGS),
            &fp);
        if (error != 0)
                return (error);
#ifdef AUDIT
        vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
        AUDIT_ARG_VNODE1(fp->f_vnode);
        VOP_UNLOCK(fp->f_vnode, 0);
#endif
        error = setfflags(td, fp->f_vnode, uap->flags);
        fdrop(fp, td);
        return (error);
}

/*
 * Common implementation code for chmod(), lchmod() and fchmod().
 */
int
setfmode(struct thread *td, struct ucred *cred, struct vnode *vp, int mode)
{
        struct mount *mp;
        struct vattr vattr;
        int error;

        if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
                return (error);
        vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
        VATTR_NULL(&vattr);
        vattr.va_mode = mode & ALLPERMS;
#ifdef MAC
        error = mac_vnode_check_setmode(cred, vp, vattr.va_mode);
        if (error == 0)
#endif
                error = VOP_SETATTR(vp, &vattr, cred);
        VOP_UNLOCK(vp, 0);
        vn_finished_write(mp);
        return (error);
}

/*
 * Change mode of a file given path name.
 */
#ifndef _SYS_SYSPROTO_H_
struct chmod_args {
        char    *path;
        int     mode;
};
#endif
int
sys_chmod(struct thread *td, struct chmod_args *uap)
{

        return (kern_fchmodat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
            uap->mode, 0));
}

#ifndef _SYS_SYSPROTO_H_
struct fchmodat_args {
        int     dirfd;
        char    *path;
        mode_t  mode;
        int     flag;
}
#endif
int
sys_fchmodat(struct thread *td, struct fchmodat_args *uap)
{
        int flag = uap->flag;
        int fd = uap->fd;
        char *path = uap->path;
        mode_t mode = uap->mode;

        if (flag & ~AT_SYMLINK_NOFOLLOW)
                return (EINVAL);

        return (kern_fchmodat(td, fd, path, UIO_USERSPACE, mode, flag));
}

/*
 * Change mode of a file given path name (don't follow links.)
 */
#ifndef _SYS_SYSPROTO_H_
struct lchmod_args {
        char    *path;
        int     mode;
};
#endif
int
sys_lchmod(struct thread *td, struct lchmod_args *uap)
{

        return (kern_fchmodat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
            uap->mode, AT_SYMLINK_NOFOLLOW));
}

int
kern_fchmodat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
    mode_t mode, int flag)
{
        struct nameidata nd;
        cap_rights_t rights;
        int error, follow;

        AUDIT_ARG_MODE(mode);
        follow = (flag & AT_SYMLINK_NOFOLLOW) ? NOFOLLOW : FOLLOW;
        NDINIT_ATRIGHTS(&nd, LOOKUP, follow | AUDITVNODE1, pathseg, path, fd,
            cap_rights_init(&rights, CAP_FCHMOD), td);
        if ((error = namei(&nd)) != 0)
                return (error);
        NDFREE(&nd, NDF_ONLY_PNBUF);
        error = setfmode(td, td->td_ucred, nd.ni_vp, mode);
        vrele(nd.ni_vp);
        return (error);
}

/*
 * Change mode of a file given a file descriptor.
 */
#ifndef _SYS_SYSPROTO_H_
struct fchmod_args {
        int     fd;
        int     mode;
};
#endif
int
sys_fchmod(struct thread *td, struct fchmod_args *uap)
{
        struct file *fp;
        cap_rights_t rights;
        int error;

        AUDIT_ARG_FD(uap->fd);
        AUDIT_ARG_MODE(uap->mode);

        error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FCHMOD), &fp);
        if (error != 0)
                return (error);
        error = fo_chmod(fp, uap->mode, td->td_ucred, td);
        fdrop(fp, td);
        return (error);
}

/*
 * Common implementation for chown(), lchown(), and fchown()
 */
int
setfown(struct thread *td, struct ucred *cred, struct vnode *vp, uid_t uid,
    gid_t gid)
{
        struct mount *mp;
        struct vattr vattr;
        int error;

        if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
                return (error);
        vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
        VATTR_NULL(&vattr);
        vattr.va_uid = uid;
        vattr.va_gid = gid;
#ifdef MAC
        error = mac_vnode_check_setowner(cred, vp, vattr.va_uid,
            vattr.va_gid);
        if (error == 0)
#endif
                error = VOP_SETATTR(vp, &vattr, cred);
        VOP_UNLOCK(vp, 0);
        vn_finished_write(mp);
        return (error);
}

/*
 * Set ownership given a path name.
 */
#ifndef _SYS_SYSPROTO_H_
struct chown_args {
        char    *path;
        int     uid;
        int     gid;
};
#endif
int
sys_chown(struct thread *td, struct chown_args *uap)
{

        return (kern_fchownat(td, AT_FDCWD, uap->path, UIO_USERSPACE, uap->uid,
            uap->gid, 0));
}

#ifndef _SYS_SYSPROTO_H_
struct fchownat_args {
        int fd;
        const char * path;
        uid_t uid;
        gid_t gid;
        int flag;
};
#endif
int
sys_fchownat(struct thread *td, struct fchownat_args *uap)
{
        int flag;

        flag = uap->flag;
        if (flag & ~AT_SYMLINK_NOFOLLOW)
                return (EINVAL);

        return (kern_fchownat(td, uap->fd, uap->path, UIO_USERSPACE, uap->uid,
            uap->gid, uap->flag));
}

int
kern_fchownat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
    int uid, int gid, int flag)
{
        struct nameidata nd;
        cap_rights_t rights;
        int error, follow;

        AUDIT_ARG_OWNER(uid, gid);
        follow = (flag & AT_SYMLINK_NOFOLLOW) ? NOFOLLOW : FOLLOW;
        NDINIT_ATRIGHTS(&nd, LOOKUP, follow | AUDITVNODE1, pathseg, path, fd,
            cap_rights_init(&rights, CAP_FCHOWN), td);

        if ((error = namei(&nd)) != 0)
                return (error);
        NDFREE(&nd, NDF_ONLY_PNBUF);
        error = setfown(td, td->td_ucred, nd.ni_vp, uid, gid);
        vrele(nd.ni_vp);
        return (error);
}

/*
 * Set ownership given a path name, do not cross symlinks.
 */
#ifndef _SYS_SYSPROTO_H_
struct lchown_args {
        char    *path;
        int     uid;
        int     gid;
};
#endif
int
sys_lchown(struct thread *td, struct lchown_args *uap)
{

        return (kern_fchownat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
            uap->uid, uap->gid, AT_SYMLINK_NOFOLLOW));
}

/*
 * Set ownership given a file descriptor.
 */
#ifndef _SYS_SYSPROTO_H_
struct fchown_args {
        int     fd;
        int     uid;
        int     gid;
};
#endif
int
sys_fchown(struct thread *td, struct fchown_args *uap)
{
        struct file *fp;
        cap_rights_t rights;
        int error;

        AUDIT_ARG_FD(uap->fd);
        AUDIT_ARG_OWNER(uap->uid, uap->gid);
        error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FCHOWN), &fp);
        if (error != 0)
                return (error);
        error = fo_chown(fp, uap->uid, uap->gid, td->td_ucred, td);
        fdrop(fp, td);
        return (error);
}

/*
 * Common implementation code for utimes(), lutimes(), and futimes().
 */
static int
getutimes(const struct timeval *usrtvp, enum uio_seg tvpseg,
    struct timespec *tsp)
{
        struct timeval tv[2];
        const struct timeval *tvp;
        int error;

        if (usrtvp == NULL) {
                vfs_timestamp(&tsp[0]);
                tsp[1] = tsp[0];
        } else {
                if (tvpseg == UIO_SYSSPACE) {
                        tvp = usrtvp;
                } else {
                        if ((error = copyin(usrtvp, tv, sizeof(tv))) != 0)
                                return (error);
                        tvp = tv;
                }

                if (tvp[0].tv_usec < 0 || tvp[0].tv_usec >= 1000000 ||
                    tvp[1].tv_usec < 0 || tvp[1].tv_usec >= 1000000)
                        return (EINVAL);
                TIMEVAL_TO_TIMESPEC(&tvp[0], &tsp[0]);
                TIMEVAL_TO_TIMESPEC(&tvp[1], &tsp[1]);
        }
        return (0);
}

/*
 * Common implementation code for futimens(), utimensat().
 */
#define UTIMENS_NULL    0x1
#define UTIMENS_EXIT    0x2
static int
getutimens(const struct timespec *usrtsp, enum uio_seg tspseg,
    struct timespec *tsp, int *retflags)
{
        struct timespec tsnow;
        int error;

        vfs_timestamp(&tsnow);
        *retflags = 0;
        if (usrtsp == NULL) {
                tsp[0] = tsnow;
                tsp[1] = tsnow;
                *retflags |= UTIMENS_NULL;
                return (0);
        }
        if (tspseg == UIO_SYSSPACE) {
                tsp[0] = usrtsp[0];
                tsp[1] = usrtsp[1];
        } else if ((error = copyin(usrtsp, tsp, sizeof(*tsp) * 2)) != 0)
                return (error);
        if (tsp[0].tv_nsec == UTIME_OMIT && tsp[1].tv_nsec == UTIME_OMIT)
                *retflags |= UTIMENS_EXIT;
        if (tsp[0].tv_nsec == UTIME_NOW && tsp[1].tv_nsec == UTIME_NOW)
                *retflags |= UTIMENS_NULL;
        if (tsp[0].tv_nsec == UTIME_OMIT)
                tsp[0].tv_sec = VNOVAL;
        else if (tsp[0].tv_nsec == UTIME_NOW)
                tsp[0] = tsnow;
        else if (tsp[0].tv_nsec < 0 || tsp[0].tv_nsec >= 1000000000L)
                return (EINVAL);
        if (tsp[1].tv_nsec == UTIME_OMIT)
                tsp[1].tv_sec = VNOVAL;
        else if (tsp[1].tv_nsec == UTIME_NOW)
                tsp[1] = tsnow;
        else if (tsp[1].tv_nsec < 0 || tsp[1].tv_nsec >= 1000000000L)
                return (EINVAL);

        return (0);
}

/*
 * Common implementation code for utimes(), lutimes(), futimes(), futimens(),
 * and utimensat().
 */
static int
setutimes(struct thread *td, struct vnode *vp, const struct timespec *ts,
    int numtimes, int nullflag)
{
        struct mount *mp;
        struct vattr vattr;
        int error, setbirthtime;

        if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
                return (error);
        vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
        setbirthtime = 0;
        if (numtimes < 3 && !VOP_GETATTR(vp, &vattr, td->td_ucred) &&
            timespeccmp(&ts[1], &vattr.va_birthtime, < ))
                setbirthtime = 1;
        VATTR_NULL(&vattr);
        vattr.va_atime = ts[0];
        vattr.va_mtime = ts[1];
        if (setbirthtime)
                vattr.va_birthtime = ts[1];
        if (numtimes > 2)
                vattr.va_birthtime = ts[2];
        if (nullflag)
                vattr.va_vaflags |= VA_UTIMES_NULL;
#ifdef MAC
        error = mac_vnode_check_setutimes(td->td_ucred, vp, vattr.va_atime,
            vattr.va_mtime);
#endif
        if (error == 0)
                error = VOP_SETATTR(vp, &vattr, td->td_ucred);
        VOP_UNLOCK(vp, 0);
        vn_finished_write(mp);
        return (error);
}

/*
 * Set the access and modification times of a file.
 */
#ifndef _SYS_SYSPROTO_H_
struct utimes_args {
        char    *path;
        struct  timeval *tptr;
};
#endif
int
sys_utimes(struct thread *td, struct utimes_args *uap)
{

        return (kern_utimesat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
            uap->tptr, UIO_USERSPACE));
}

#ifndef _SYS_SYSPROTO_H_
struct futimesat_args {
        int fd;
        const char * path;
        const struct timeval * times;
};
#endif
int
sys_futimesat(struct thread *td, struct futimesat_args *uap)
{

        return (kern_utimesat(td, uap->fd, uap->path, UIO_USERSPACE,
            uap->times, UIO_USERSPACE));
}

int
kern_utimesat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
    struct timeval *tptr, enum uio_seg tptrseg)
{
        struct nameidata nd;
        struct timespec ts[2];
        cap_rights_t rights;
        int error;

        if ((error = getutimes(tptr, tptrseg, ts)) != 0)
                return (error);
        NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path, fd,
            cap_rights_init(&rights, CAP_FUTIMES), td);

        if ((error = namei(&nd)) != 0)
                return (error);
        NDFREE(&nd, NDF_ONLY_PNBUF);
        error = setutimes(td, nd.ni_vp, ts, 2, tptr == NULL);
        vrele(nd.ni_vp);
        return (error);
}

/*
 * Set the access and modification times of a file.
 */
#ifndef _SYS_SYSPROTO_H_
struct lutimes_args {
        char    *path;
        struct  timeval *tptr;
};
#endif
int
sys_lutimes(struct thread *td, struct lutimes_args *uap)
{

        return (kern_lutimes(td, uap->path, UIO_USERSPACE, uap->tptr,
            UIO_USERSPACE));
}

int
kern_lutimes(struct thread *td, char *path, enum uio_seg pathseg,
    struct timeval *tptr, enum uio_seg tptrseg)
{
        struct timespec ts[2];
        struct nameidata nd;
        int error;

        if ((error = getutimes(tptr, tptrseg, ts)) != 0)
                return (error);
        NDINIT(&nd, LOOKUP, NOFOLLOW | AUDITVNODE1, pathseg, path, td);
        if ((error = namei(&nd)) != 0)
                return (error);
        NDFREE(&nd, NDF_ONLY_PNBUF);
        error = setutimes(td, nd.ni_vp, ts, 2, tptr == NULL);
        vrele(nd.ni_vp);
        return (error);
}

/*
 * Set the access and modification times of a file.
 */
#ifndef _SYS_SYSPROTO_H_
struct futimes_args {
        int     fd;
        struct  timeval *tptr;
};
#endif
int
sys_futimes(struct thread *td, struct futimes_args *uap)
{

        return (kern_futimes(td, uap->fd, uap->tptr, UIO_USERSPACE));
}

int
kern_futimes(struct thread *td, int fd, struct timeval *tptr,
    enum uio_seg tptrseg)
{
        struct timespec ts[2];
        struct file *fp;
        cap_rights_t rights;
        int error;

        AUDIT_ARG_FD(fd);
        error = getutimes(tptr, tptrseg, ts);
        if (error != 0)
                return (error);
        error = getvnode(td, fd, cap_rights_init(&rights, CAP_FUTIMES), &fp);
        if (error != 0)
                return (error);
#ifdef AUDIT
        vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
        AUDIT_ARG_VNODE1(fp->f_vnode);
        VOP_UNLOCK(fp->f_vnode, 0);
#endif
        error = setutimes(td, fp->f_vnode, ts, 2, tptr == NULL);
        fdrop(fp, td);
        return (error);
}

int
sys_futimens(struct thread *td, struct futimens_args *uap)
{

        return (kern_futimens(td, uap->fd, uap->times, UIO_USERSPACE));
}

int
kern_futimens(struct thread *td, int fd, struct timespec *tptr,
    enum uio_seg tptrseg)
{
        struct timespec ts[2];
        struct file *fp;
        cap_rights_t rights;
        int error, flags;

        AUDIT_ARG_FD(fd);
        error = getutimens(tptr, tptrseg, ts, &flags);
        if (error != 0)
                return (error);
        if (flags & UTIMENS_EXIT)
                return (0);
        error = getvnode(td, fd, cap_rights_init(&rights, CAP_FUTIMES), &fp);
        if (error != 0)
                return (error);
#ifdef AUDIT
        vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
        AUDIT_ARG_VNODE1(fp->f_vnode);
        VOP_UNLOCK(fp->f_vnode, 0);
#endif
        error = setutimes(td, fp->f_vnode, ts, 2, flags & UTIMENS_NULL);
        fdrop(fp, td);
        return (error);
}

int
sys_utimensat(struct thread *td, struct utimensat_args *uap)
{

        return (kern_utimensat(td, uap->fd, uap->path, UIO_USERSPACE,
            uap->times, UIO_USERSPACE, uap->flag));
}

int
kern_utimensat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
    struct timespec *tptr, enum uio_seg tptrseg, int flag)
{
        struct nameidata nd;
        struct timespec ts[2];
        cap_rights_t rights;
        int error, flags;

        if (flag & ~AT_SYMLINK_NOFOLLOW)
                return (EINVAL);

        if ((error = getutimens(tptr, tptrseg, ts, &flags)) != 0)
                return (error);
        NDINIT_ATRIGHTS(&nd, LOOKUP, ((flag & AT_SYMLINK_NOFOLLOW) ? NOFOLLOW :
            FOLLOW) | AUDITVNODE1, pathseg, path, fd,
            cap_rights_init(&rights, CAP_FUTIMES), td);
        if ((error = namei(&nd)) != 0)
                return (error);
        /*
         * We are allowed to call namei() regardless of 2xUTIME_OMIT.
         * POSIX states:
         * "If both tv_nsec fields are UTIME_OMIT... EACCESS may be detected."
         * "Search permission is denied by a component of the path prefix."
         */
        NDFREE(&nd, NDF_ONLY_PNBUF);
        if ((flags & UTIMENS_EXIT) == 0)
                error = setutimes(td, nd.ni_vp, ts, 2, flags & UTIMENS_NULL);
        vrele(nd.ni_vp);
        return (error);
}

/*
 * Truncate a file given its path name.
 */
#ifndef _SYS_SYSPROTO_H_
struct truncate_args {
        char    *path;
        int     pad;
        off_t   length;
};
#endif
int
sys_truncate(struct thread *td, struct truncate_args *uap)
{

        return (kern_truncate(td, uap->path, UIO_USERSPACE, uap->length));
}

int
kern_truncate(struct thread *td, char *path, enum uio_seg pathseg, off_t length)
{
        struct mount *mp;
        struct vnode *vp;
        void *rl_cookie;
        struct vattr vattr;
        struct nameidata nd;
        int error;

        if (length < 0)
                return(EINVAL);
        NDINIT(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path, td);
        if ((error = namei(&nd)) != 0)
                return (error);
        vp = nd.ni_vp;
        rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
        if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) {
                vn_rangelock_unlock(vp, rl_cookie);
                vrele(vp);
                return (error);
        }
        NDFREE(&nd, NDF_ONLY_PNBUF);
        vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
        if (vp->v_type == VDIR)
                error = EISDIR;
#ifdef MAC
        else if ((error = mac_vnode_check_write(td->td_ucred, NOCRED, vp))) {
        }
#endif
        else if ((error = vn_writechk(vp)) == 0 &&
            (error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td)) == 0) {
                VATTR_NULL(&vattr);
                vattr.va_size = length;
                error = VOP_SETATTR(vp, &vattr, td->td_ucred);
        }
        VOP_UNLOCK(vp, 0);
        vn_finished_write(mp);
        vn_rangelock_unlock(vp, rl_cookie);
        vrele(vp);
        return (error);
}

#if defined(COMPAT_43)
/*
 * Truncate a file given its path name.
 */
#ifndef _SYS_SYSPROTO_H_
struct otruncate_args {
        char    *path;
        long    length;
};
#endif
int
otruncate(struct thread *td, struct otruncate_args *uap)
{

        return (kern_truncate(td, uap->path, UIO_USERSPACE, uap->length));
}
#endif /* COMPAT_43 */

#if defined(COMPAT_FREEBSD6)
/* Versions with the pad argument */
int
freebsd6_truncate(struct thread *td, struct freebsd6_truncate_args *uap)
{

        return (kern_truncate(td, uap->path, UIO_USERSPACE, uap->length));
}

int
freebsd6_ftruncate(struct thread *td, struct freebsd6_ftruncate_args *uap)
{

        return (kern_ftruncate(td, uap->fd, uap->length));
}
#endif

int
kern_fsync(struct thread *td, int fd, bool fullsync)
{
        struct vnode *vp;
        struct mount *mp;
        struct file *fp;
        cap_rights_t rights;
        int error, lock_flags;

        AUDIT_ARG_FD(fd);
        error = getvnode(td, fd, cap_rights_init(&rights, CAP_FSYNC), &fp);
        if (error != 0)
                return (error);
        vp = fp->f_vnode;
#if 0
        if (!fullsync)
                /* XXXKIB: compete outstanding aio writes */;
#endif
        error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
        if (error != 0)
                goto drop;
        if (MNT_SHARED_WRITES(mp) ||
            ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount))) {
                lock_flags = LK_SHARED;
        } else {
                lock_flags = LK_EXCLUSIVE;
        }
        vn_lock(vp, lock_flags | LK_RETRY);
        AUDIT_ARG_VNODE1(vp);
        if (vp->v_object != NULL) {
                VM_OBJECT_WLOCK(vp->v_object);
                vm_object_page_clean(vp->v_object, 0, 0, 0);
                VM_OBJECT_WUNLOCK(vp->v_object);
        }
        error = fullsync ? VOP_FSYNC(vp, MNT_WAIT, td) : VOP_FDATASYNC(vp, td);
        VOP_UNLOCK(vp, 0);
        vn_finished_write(mp);
drop:
        fdrop(fp, td);
        return (error);
}

/*
 * Sync an open file.
 */
#ifndef _SYS_SYSPROTO_H_
struct fsync_args {
        int     fd;
};
#endif
int
sys_fsync(struct thread *td, struct fsync_args *uap)
{

        return (kern_fsync(td, uap->fd, true));
}

int
sys_fdatasync(struct thread *td, struct fdatasync_args *uap)
{

        return (kern_fsync(td, uap->fd, false));
}

/*
 * Rename files.  Source and destination must either both be directories, or
 * both not be directories.  If target is a directory, it must be empty.
 */
#ifndef _SYS_SYSPROTO_H_
struct rename_args {
        char    *from;
        char    *to;
};
#endif
int
sys_rename(struct thread *td, struct rename_args *uap)
{

        return (kern_renameat(td, AT_FDCWD, uap->from, AT_FDCWD,
            uap->to, UIO_USERSPACE));
}

#ifndef _SYS_SYSPROTO_H_
struct renameat_args {
        int     oldfd;
        char    *old;
        int     newfd;
        char    *new;
};
#endif
int
sys_renameat(struct thread *td, struct renameat_args *uap)
{

        return (kern_renameat(td, uap->oldfd, uap->old, uap->newfd, uap->new,
            UIO_USERSPACE));
}

int
kern_renameat(struct thread *td, int oldfd, char *old, int newfd, char *new,
    enum uio_seg pathseg)
{
        struct mount *mp = NULL;
        struct vnode *tvp, *fvp, *tdvp;
        struct nameidata fromnd, tond;
        cap_rights_t rights;
        int error;

again:
        bwillwrite();
#ifdef MAC
        NDINIT_ATRIGHTS(&fromnd, DELETE, LOCKPARENT | LOCKLEAF | SAVESTART |
            AUDITVNODE1, pathseg, old, oldfd,
            cap_rights_init(&rights, CAP_RENAMEAT_SOURCE), td);
#else
        NDINIT_ATRIGHTS(&fromnd, DELETE, WANTPARENT | SAVESTART | AUDITVNODE1,
            pathseg, old, oldfd,
            cap_rights_init(&rights, CAP_RENAMEAT_SOURCE), td);
#endif

        if ((error = namei(&fromnd)) != 0)
                return (error);
#ifdef MAC
        error = mac_vnode_check_rename_from(td->td_ucred, fromnd.ni_dvp,
            fromnd.ni_vp, &fromnd.ni_cnd);
        VOP_UNLOCK(fromnd.ni_dvp, 0);
        if (fromnd.ni_dvp != fromnd.ni_vp)
                VOP_UNLOCK(fromnd.ni_vp, 0);
#endif
        fvp = fromnd.ni_vp;
        NDINIT_ATRIGHTS(&tond, RENAME, LOCKPARENT | LOCKLEAF | NOCACHE |
            SAVESTART | AUDITVNODE2, pathseg, new, newfd,
            cap_rights_init(&rights, CAP_RENAMEAT_TARGET), td);
        if (fromnd.ni_vp->v_type == VDIR)
                tond.ni_cnd.cn_flags |= WILLBEDIR;
        if ((error = namei(&tond)) != 0) {
                /* Translate error code for rename("dir1", "dir2/."). */
                if (error == EISDIR && fvp->v_type == VDIR)
                        error = EINVAL;
                NDFREE(&fromnd, NDF_ONLY_PNBUF);
                vrele(fromnd.ni_dvp);
                vrele(fvp);
                goto out1;
        }
        tdvp = tond.ni_dvp;
        tvp = tond.ni_vp;
        error = vn_start_write(fvp, &mp, V_NOWAIT);
        if (error != 0) {
                NDFREE(&fromnd, NDF_ONLY_PNBUF);
                NDFREE(&tond, NDF_ONLY_PNBUF);
                if (tvp != NULL)
                        vput(tvp);
                if (tdvp == tvp)
                        vrele(tdvp);
                else
                        vput(tdvp);
                vrele(fromnd.ni_dvp);
                vrele(fvp);
                vrele(tond.ni_startdir);
                if (fromnd.ni_startdir != NULL)
                        vrele(fromnd.ni_startdir);
                error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH);
                if (error != 0)
                        return (error);
                goto again;
        }
        if (tvp != NULL) {
                if (fvp->v_type == VDIR && tvp->v_type != VDIR) {
                        error = ENOTDIR;
                        goto out;
                } else if (fvp->v_type != VDIR && tvp->v_type == VDIR) {
                        error = EISDIR;
                        goto out;
                }
#ifdef CAPABILITIES
                if (newfd != AT_FDCWD) {
                        /*
                         * If the target already exists we require CAP_UNLINKAT
                         * from 'newfd'.
                         */
                        error = cap_check(&tond.ni_filecaps.fc_rights,
                            cap_rights_init(&rights, CAP_UNLINKAT));
                        if (error != 0)
                                goto out;
                }
#endif
        }
        if (fvp == tdvp) {
                error = EINVAL;
                goto out;
        }
        /*
         * If the source is the same as the destination (that is, if they
         * are links to the same vnode), then there is nothing to do.
         */
        if (fvp == tvp)
                error = -1;
#ifdef MAC
        else
                error = mac_vnode_check_rename_to(td->td_ucred, tdvp,
                    tond.ni_vp, fromnd.ni_dvp == tdvp, &tond.ni_cnd);
#endif
out:
        if (error == 0) {
                error = VOP_RENAME(fromnd.ni_dvp, fromnd.ni_vp, &fromnd.ni_cnd,
                    tond.ni_dvp, tond.ni_vp, &tond.ni_cnd);
                NDFREE(&fromnd, NDF_ONLY_PNBUF);
                NDFREE(&tond, NDF_ONLY_PNBUF);
        } else {
                NDFREE(&fromnd, NDF_ONLY_PNBUF);
                NDFREE(&tond, NDF_ONLY_PNBUF);
                if (tvp != NULL)
                        vput(tvp);
                if (tdvp == tvp)
                        vrele(tdvp);
                else
                        vput(tdvp);
                vrele(fromnd.ni_dvp);
                vrele(fvp);
        }
        vrele(tond.ni_startdir);
        vn_finished_write(mp);
out1:
        if (fromnd.ni_startdir)
                vrele(fromnd.ni_startdir);
        if (error == -1)
                return (0);
        return (error);
}

/*
 * Make a directory file.
 */
#ifndef _SYS_SYSPROTO_H_
struct mkdir_args {
        char    *path;
        int     mode;
};
#endif
int
sys_mkdir(struct thread *td, struct mkdir_args *uap)
{

        return (kern_mkdirat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
            uap->mode));
}

#ifndef _SYS_SYSPROTO_H_
struct mkdirat_args {
        int     fd;
        char    *path;
        mode_t  mode;
};
#endif
int
sys_mkdirat(struct thread *td, struct mkdirat_args *uap)
{

        return (kern_mkdirat(td, uap->fd, uap->path, UIO_USERSPACE, uap->mode));
}

int
kern_mkdirat(struct thread *td, int fd, char *path, enum uio_seg segflg,
    int mode)
{
        struct mount *mp;
        struct vnode *vp;
        struct vattr vattr;
        struct nameidata nd;
        cap_rights_t rights;
        int error;

        AUDIT_ARG_MODE(mode);
restart:
        bwillwrite();
        NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | SAVENAME | AUDITVNODE1 |
            NOCACHE, segflg, path, fd, cap_rights_init(&rights, CAP_MKDIRAT),
            td);
        nd.ni_cnd.cn_flags |= WILLBEDIR;
        if ((error = namei(&nd)) != 0)
                return (error);
        vp = nd.ni_vp;
        if (vp != NULL) {
                NDFREE(&nd, NDF_ONLY_PNBUF);
                /*
                 * XXX namei called with LOCKPARENT but not LOCKLEAF has
                 * the strange behaviour of leaving the vnode unlocked
                 * if the target is the same vnode as the parent.
                 */
                if (vp == nd.ni_dvp)
                        vrele(nd.ni_dvp);
                else
                        vput(nd.ni_dvp);
                vrele(vp);
                return (EEXIST);
        }
        if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
                NDFREE(&nd, NDF_ONLY_PNBUF);
                vput(nd.ni_dvp);
                if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
                        return (error);
                goto restart;
        }
        VATTR_NULL(&vattr);
        vattr.va_type = VDIR;
        vattr.va_mode = (mode & ACCESSPERMS) &~ td->td_proc->p_fd->fd_cmask;
#ifdef MAC
        error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
            &vattr);
        if (error != 0)
                goto out;
#endif
        error = VOP_MKDIR(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
#ifdef MAC
out:
#endif
        NDFREE(&nd, NDF_ONLY_PNBUF);
        vput(nd.ni_dvp);
        if (error == 0)
                vput(nd.ni_vp);
        vn_finished_write(mp);
        return (error);
}

/*
 * Remove a directory file.
 */
#ifndef _SYS_SYSPROTO_H_
struct rmdir_args {
        char    *path;
};
#endif
int
sys_rmdir(struct thread *td, struct rmdir_args *uap)
{

        return (kern_rmdirat(td, AT_FDCWD, uap->path, UIO_USERSPACE));
}

int
kern_rmdirat(struct thread *td, int fd, char *path, enum uio_seg pathseg)
{
        struct mount *mp;
        struct vnode *vp;
        struct nameidata nd;
        cap_rights_t rights;
        int error;

restart:
        bwillwrite();
        NDINIT_ATRIGHTS(&nd, DELETE, LOCKPARENT | LOCKLEAF | AUDITVNODE1,
            pathseg, path, fd, cap_rights_init(&rights, CAP_UNLINKAT), td);
        if ((error = namei(&nd)) != 0)
                return (error);
        vp = nd.ni_vp;
        if (vp->v_type != VDIR) {
                error = ENOTDIR;
                goto out;
        }
        /*
         * No rmdir "." please.
         */
        if (nd.ni_dvp == vp) {
                error = EINVAL;
                goto out;
        }
        /*
         * The root of a mounted filesystem cannot be deleted.
         */
        if (vp->v_vflag & VV_ROOT) {
                error = EBUSY;
                goto out;
        }
#ifdef MAC
        error = mac_vnode_check_unlink(td->td_ucred, nd.ni_dvp, vp,
            &nd.ni_cnd);
        if (error != 0)
                goto out;
#endif
        if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
                NDFREE(&nd, NDF_ONLY_PNBUF);
                vput(vp);
                if (nd.ni_dvp == vp)
                        vrele(nd.ni_dvp);
                else
                        vput(nd.ni_dvp);
                if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
                        return (error);
                goto restart;
        }
        vfs_notify_upper(vp, VFS_NOTIFY_UPPER_UNLINK);
        error = VOP_RMDIR(nd.ni_dvp, nd.ni_vp, &nd.ni_cnd);
        vn_finished_write(mp);
out:
        NDFREE(&nd, NDF_ONLY_PNBUF);
        vput(vp);
        if (nd.ni_dvp == vp)
                vrele(nd.ni_dvp);
        else
                vput(nd.ni_dvp);
        return (error);
}

#if defined(COMPAT_43) || defined(COMPAT_FREEBSD11)
int
freebsd11_kern_getdirentries(struct thread *td, int fd, char *ubuf, u_int count,
    long *basep, void (*func)(struct freebsd11_dirent *))
{
        struct freebsd11_dirent dstdp;
        struct dirent *dp, *edp;
        char *dirbuf;
        off_t base;
        ssize_t resid, ucount;
        int error;

        /* XXX arbitrary sanity limit on `count'. */
        count = min(count, 64 * 1024);

        dirbuf = malloc(count, M_TEMP, M_WAITOK);

        error = kern_getdirentries(td, fd, dirbuf, count, &base, &resid,
            UIO_SYSSPACE);
        if (error != 0)
                goto done;
        if (basep != NULL)
                *basep = base;

        ucount = 0;
        for (dp = (struct dirent *)dirbuf,
            edp = (struct dirent *)&dirbuf[count - resid];
            ucount < count && dp < edp; ) {
                if (dp->d_reclen == 0)
                        break;
                MPASS(dp->d_reclen >= _GENERIC_DIRLEN(0));
                if (dp->d_namlen >= sizeof(dstdp.d_name))
                        continue;
                dstdp.d_type = dp->d_type;
                dstdp.d_namlen = dp->d_namlen;
                dstdp.d_fileno = dp->d_fileno;          /* truncate */
                if (dstdp.d_fileno != dp->d_fileno) {
                        switch (ino64_trunc_error) {
                        default:
                        case 0:
                                break;
                        case 1:
                                error = EOVERFLOW;
                                goto done;
                        case 2:
                                dstdp.d_fileno = UINT32_MAX;
                                break;
                        }
                }
                dstdp.d_reclen = sizeof(dstdp) - sizeof(dstdp.d_name) +
                    ((dp->d_namlen + 1 + 3) &~ 3);
                bcopy(dp->d_name, dstdp.d_name, dstdp.d_namlen);
                bzero(dstdp.d_name + dstdp.d_namlen,
                    dstdp.d_reclen - offsetof(struct freebsd11_dirent, d_name) -
                    dstdp.d_namlen);
                MPASS(dstdp.d_reclen <= dp->d_reclen);
                MPASS(ucount + dstdp.d_reclen <= count);
                if (func != NULL)
                        func(&dstdp);
                error = copyout(&dstdp, ubuf + ucount, dstdp.d_reclen);
                if (error != 0)
                        break;
                dp = (struct dirent *)((char *)dp + dp->d_reclen);
                ucount += dstdp.d_reclen;
        }

done:
        free(dirbuf, M_TEMP);
        if (error == 0)
                td->td_retval[0] = ucount;
        return (error);
}
#endif /* COMPAT */

#ifdef COMPAT_43
static void
ogetdirentries_cvt(struct freebsd11_dirent *dp)
{
#if (BYTE_ORDER == LITTLE_ENDIAN)
        /*
         * The expected low byte of dp->d_namlen is our dp->d_type.
         * The high MBZ byte of dp->d_namlen is our dp->d_namlen.
         */
        dp->d_type = dp->d_namlen;
        dp->d_namlen = 0;
#else
        /*
         * The dp->d_type is the high byte of the expected dp->d_namlen,
         * so must be zero'ed.
         */
        dp->d_type = 0;
#endif
}

/*
 * Read a block of directory entries in a filesystem independent format.
 */
#ifndef _SYS_SYSPROTO_H_
struct ogetdirentries_args {
        int     fd;
        char    *buf;
        u_int   count;
        long    *basep;
};
#endif
int
ogetdirentries(struct thread *td, struct ogetdirentries_args *uap)
{
        long loff;
        int error;

        error = kern_ogetdirentries(td, uap, &loff);
        if (error == 0)
                error = copyout(&loff, uap->basep, sizeof(long));
        return (error);
}

int
kern_ogetdirentries(struct thread *td, struct ogetdirentries_args *uap,
    long *ploff)
{
        long base;
        int error;

        /* XXX arbitrary sanity limit on `count'. */
        if (uap->count > 64 * 1024)
                return (EINVAL);

        error = freebsd11_kern_getdirentries(td, uap->fd, uap->buf, uap->count,
            &base, ogetdirentries_cvt);

        if (error == 0 && uap->basep != NULL)
                error = copyout(&base, uap->basep, sizeof(long));

        return (error);
}
#endif /* COMPAT_43 */

#if defined(COMPAT_FREEBSD11)
#ifndef _SYS_SYSPROTO_H_
struct freebsd11_getdirentries_args {
        int     fd;
        char    *buf;
        u_int   count;
        long    *basep;
};
#endif
int
freebsd11_getdirentries(struct thread *td,
    struct freebsd11_getdirentries_args *uap)
{
        long base;
        int error;

        error = freebsd11_kern_getdirentries(td, uap->fd, uap->buf, uap->count,
            &base, NULL);

        if (error == 0 && uap->basep != NULL)
                error = copyout(&base, uap->basep, sizeof(long));
        return (error);
}

int
freebsd11_getdents(struct thread *td, struct freebsd11_getdents_args *uap)
{
        struct freebsd11_getdirentries_args ap;

        ap.fd = uap->fd;
        ap.buf = uap->buf;
        ap.count = uap->count;
        ap.basep = NULL;
        return (freebsd11_getdirentries(td, &ap));
}
#endif /* COMPAT_FREEBSD11 */

/*
 * Read a block of directory entries in a filesystem independent format.
 */
int
sys_getdirentries(struct thread *td, struct getdirentries_args *uap)
{
        off_t base;
        int error;

        error = kern_getdirentries(td, uap->fd, uap->buf, uap->count, &base,
            NULL, UIO_USERSPACE);
        if (error != 0)
                return (error);
        if (uap->basep != NULL)
                error = copyout(&base, uap->basep, sizeof(off_t));
        return (error);
}

int
kern_getdirentries(struct thread *td, int fd, char *buf, size_t count,
    off_t *basep, ssize_t *residp, enum uio_seg bufseg)
{
        struct vnode *vp;
        struct file *fp;
        struct uio auio;
        struct iovec aiov;
        cap_rights_t rights;
        off_t loff;
        int error, eofflag;
        off_t foffset;

        AUDIT_ARG_FD(fd);
        if (count > IOSIZE_MAX)
                return (EINVAL);
        auio.uio_resid = count;
        error = getvnode(td, fd, cap_rights_init(&rights, CAP_READ), &fp);
        if (error != 0)
                return (error);
        if ((fp->f_flag & FREAD) == 0) {
                fdrop(fp, td);
                return (EBADF);
        }
        vp = fp->f_vnode;
        foffset = foffset_lock(fp, 0);
unionread:
        if (vp->v_type != VDIR) {
                error = EINVAL;
                goto fail;
        }
        aiov.iov_base = buf;
        aiov.iov_len = count;
        auio.uio_iov = &aiov;
        auio.uio_iovcnt = 1;
        auio.uio_rw = UIO_READ;
        auio.uio_segflg = bufseg;
        auio.uio_td = td;
        vn_lock(vp, LK_SHARED | LK_RETRY);
        AUDIT_ARG_VNODE1(vp);
        loff = auio.uio_offset = foffset;
#ifdef MAC
        error = mac_vnode_check_readdir(td->td_ucred, vp);
        if (error == 0)
#endif
                error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, NULL,
                    NULL);
        foffset = auio.uio_offset;
        if (error != 0) {
                VOP_UNLOCK(vp, 0);
                goto fail;
        }
        if (count == auio.uio_resid &&
            (vp->v_vflag & VV_ROOT) &&
            (vp->v_mount->mnt_flag & MNT_UNION)) {
                struct vnode *tvp = vp;

                vp = vp->v_mount->mnt_vnodecovered;
                VREF(vp);
                fp->f_vnode = vp;
                fp->f_data = vp;
                foffset = 0;
                vput(tvp);
                goto unionread;
        }
        VOP_UNLOCK(vp, 0);
        *basep = loff;
        if (residp != NULL)
                *residp = auio.uio_resid;
        td->td_retval[0] = count - auio.uio_resid;
fail:
        foffset_unlock(fp, foffset, 0);
        fdrop(fp, td);
        return (error);
}

/*
 * Set the mode mask for creation of filesystem nodes.
 */
#ifndef _SYS_SYSPROTO_H_
struct umask_args {
        int     newmask;
};
#endif
int
sys_umask(struct thread *td, struct umask_args *uap)
{
        struct filedesc *fdp;

        fdp = td->td_proc->p_fd;
        FILEDESC_XLOCK(fdp);
        td->td_retval[0] = fdp->fd_cmask;
        fdp->fd_cmask = uap->newmask & ALLPERMS;
        FILEDESC_XUNLOCK(fdp);
        return (0);
}

/*
 * Void all references to file by ripping underlying filesystem away from
 * vnode.
 */
#ifndef _SYS_SYSPROTO_H_
struct revoke_args {
        char    *path;
};
#endif
int
sys_revoke(struct thread *td, struct revoke_args *uap)
{
        struct vnode *vp;
        struct vattr vattr;
        struct nameidata nd;
        int error;

        NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_USERSPACE,
            uap->path, td);
        if ((error = namei(&nd)) != 0)
                return (error);
        vp = nd.ni_vp;
        NDFREE(&nd, NDF_ONLY_PNBUF);
        if (vp->v_type != VCHR || vp->v_rdev == NULL) {
                error = EINVAL;
                goto out;
        }
#ifdef MAC
        error = mac_vnode_check_revoke(td->td_ucred, vp);
        if (error != 0)
                goto out;
#endif
        error = VOP_GETATTR(vp, &vattr, td->td_ucred);
        if (error != 0)
                goto out;
        if (td->td_ucred->cr_uid != vattr.va_uid) {
                error = priv_check(td, PRIV_VFS_ADMIN);
                if (error != 0)
                        goto out;
        }
        if (vcount(vp) > 1)
                VOP_REVOKE(vp, REVOKEALL);
out:
        vput(vp);
        return (error);
}

/*
 * Convert a user file descriptor to a kernel file entry and check that, if it
 * is a capability, the correct rights are present. A reference on the file
 * entry is held upon returning.
 */
int
getvnode(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp)
{
        struct file *fp;
        int error;

        error = fget_unlocked(td->td_proc->p_fd, fd, rightsp, &fp, NULL);
        if (error != 0)
                return (error);

        /*
         * The file could be not of the vnode type, or it may be not
         * yet fully initialized, in which case the f_vnode pointer
         * may be set, but f_ops is still badfileops.  E.g.,
         * devfs_open() transiently create such situation to
         * facilitate csw d_fdopen().
         *
         * Dupfdopen() handling in kern_openat() installs the
         * half-baked file into the process descriptor table, allowing
         * other thread to dereference it. Guard against the race by
         * checking f_ops.
         */
        if (fp->f_vnode == NULL || fp->f_ops == &badfileops) {
                fdrop(fp, td);
                return (EINVAL);
        }
        *fpp = fp;
        return (0);
}


/*
 * Get an (NFS) file handle.
 */
#ifndef _SYS_SYSPROTO_H_
struct lgetfh_args {
        char    *fname;
        fhandle_t *fhp;
};
#endif
int
sys_lgetfh(struct thread *td, struct lgetfh_args *uap)
{
        struct nameidata nd;
        fhandle_t fh;
        struct vnode *vp;
        int error;

        error = priv_check(td, PRIV_VFS_GETFH);
        if (error != 0)
                return (error);
        NDINIT(&nd, LOOKUP, NOFOLLOW | LOCKLEAF | AUDITVNODE1, UIO_USERSPACE,
            uap->fname, td);
        error = namei(&nd);
        if (error != 0)
                return (error);
        NDFREE(&nd, NDF_ONLY_PNBUF);
        vp = nd.ni_vp;
        bzero(&fh, sizeof(fh));
        fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
        error = VOP_VPTOFH(vp, &fh.fh_fid);
        vput(vp);
        if (error == 0)
                error = copyout(&fh, uap->fhp, sizeof (fh));
        return (error);
}

#ifndef _SYS_SYSPROTO_H_
struct getfh_args {
        char    *fname;
        fhandle_t *fhp;
};
#endif
int
sys_getfh(struct thread *td, struct getfh_args *uap)
{
        struct nameidata nd;
        fhandle_t fh;
        struct vnode *vp;
        int error;

        error = priv_check(td, PRIV_VFS_GETFH);
        if (error != 0)
                return (error);
        NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_USERSPACE,
            uap->fname, td);
        error = namei(&nd);
        if (error != 0)
                return (error);
        NDFREE(&nd, NDF_ONLY_PNBUF);
        vp = nd.ni_vp;
        bzero(&fh, sizeof(fh));
        fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
        error = VOP_VPTOFH(vp, &fh.fh_fid);
        vput(vp);
        if (error == 0)
                error = copyout(&fh, uap->fhp, sizeof (fh));
        return (error);
}

/*
 * syscall for the rpc.lockd to use to translate a NFS file handle into an
 * open descriptor.
 *
 * warning: do not remove the priv_check() call or this becomes one giant
 * security hole.
 */
#ifndef _SYS_SYSPROTO_H_
struct fhopen_args {
        const struct fhandle *u_fhp;
        int flags;
};
#endif
int
sys_fhopen(struct thread *td, struct fhopen_args *uap)
{
        struct mount *mp;
        struct vnode *vp;
        struct fhandle fhp;
        struct file *fp;
        int fmode, error;
        int indx;

        error = priv_check(td, PRIV_VFS_FHOPEN);
        if (error != 0)
                return (error);
        indx = -1;
        fmode = FFLAGS(uap->flags);
        /* why not allow a non-read/write open for our lockd? */
        if (((fmode & (FREAD | FWRITE)) == 0) || (fmode & O_CREAT))
                return (EINVAL);
        error = copyin(uap->u_fhp, &fhp, sizeof(fhp));
        if (error != 0)
                return(error);
        /* find the mount point */
        mp = vfs_busyfs(&fhp.fh_fsid);
        if (mp == NULL)
                return (ESTALE);
        /* now give me my vnode, it gets returned to me locked */
        error = VFS_FHTOVP(mp, &fhp.fh_fid, LK_EXCLUSIVE, &vp);
        vfs_unbusy(mp);
        if (error != 0)
                return (error);

        error = falloc_noinstall(td, &fp);
        if (error != 0) {
                vput(vp);
                return (error);
        }
        /*
         * An extra reference on `fp' has been held for us by
         * falloc_noinstall().
         */

#ifdef INVARIANTS
        td->td_dupfd = -1;
#endif
        error = vn_open_vnode(vp, fmode, td->td_ucred, td, fp);
        if (error != 0) {
                KASSERT(fp->f_ops == &badfileops,
                    ("VOP_OPEN in fhopen() set f_ops"));
                KASSERT(td->td_dupfd < 0,
                    ("fhopen() encountered fdopen()"));

                vput(vp);
                goto bad;
        }
#ifdef INVARIANTS
        td->td_dupfd = 0;
#endif
        fp->f_vnode = vp;
        fp->f_seqcount = 1;
        finit(fp, (fmode & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, vp,
            &vnops);
        VOP_UNLOCK(vp, 0);
        if ((fmode & O_TRUNC) != 0) {
                error = fo_truncate(fp, 0, td->td_ucred, td);
                if (error != 0)
                        goto bad;
        }

        error = finstall(td, fp, &indx, fmode, NULL);
bad:
        fdrop(fp, td);
        td->td_retval[0] = indx;
        return (error);
}

/*
 * Stat an (NFS) file handle.
 */
#ifndef _SYS_SYSPROTO_H_
struct fhstat_args {
        struct fhandle *u_fhp;
        struct stat *sb;
};
#endif
int
sys_fhstat(struct thread *td, struct fhstat_args *uap)
{
        struct stat sb;
        struct fhandle fh;
        int error;

        error = copyin(uap->u_fhp, &fh, sizeof(fh));
        if (error != 0)
                return (error);
        error = kern_fhstat(td, fh, &sb);
        if (error == 0)
                error = copyout(&sb, uap->sb, sizeof(sb));
        return (error);
}

int
kern_fhstat(struct thread *td, struct fhandle fh, struct stat *sb)
{
        struct mount *mp;
        struct vnode *vp;
        int error;

        error = priv_check(td, PRIV_VFS_FHSTAT);
        if (error != 0)
                return (error);
        if ((mp = vfs_busyfs(&fh.fh_fsid)) == NULL)
                return (ESTALE);
        error = VFS_FHTOVP(mp, &fh.fh_fid, LK_EXCLUSIVE, &vp);
        vfs_unbusy(mp);
        if (error != 0)
                return (error);
        error = vn_stat(vp, sb, td->td_ucred, NOCRED, td);
        vput(vp);
        return (error);
}

/*
 * Implement fstatfs() for (NFS) file handles.
 */
#ifndef _SYS_SYSPROTO_H_
struct fhstatfs_args {
        struct fhandle *u_fhp;
        struct statfs *buf;
};
#endif
int
sys_fhstatfs(struct thread *td, struct fhstatfs_args *uap)
{
        struct statfs *sfp;
        fhandle_t fh;
        int error;

        error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
        if (error != 0)
                return (error);
        sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
        error = kern_fhstatfs(td, fh, sfp);
        if (error == 0)
                error = copyout(sfp, uap->buf, sizeof(*sfp));
        free(sfp, M_STATFS);
        return (error);
}

int
kern_fhstatfs(struct thread *td, fhandle_t fh, struct statfs *buf)
{
        struct statfs *sp;
        struct mount *mp;
        struct vnode *vp;
        int error;

        error = priv_check(td, PRIV_VFS_FHSTATFS);
        if (error != 0)
                return (error);
        if ((mp = vfs_busyfs(&fh.fh_fsid)) == NULL)
                return (ESTALE);
        error = VFS_FHTOVP(mp, &fh.fh_fid, LK_EXCLUSIVE, &vp);
        if (error != 0) {
                vfs_unbusy(mp);
                return (error);
        }
        vput(vp);
        error = prison_canseemount(td->td_ucred, mp);
        if (error != 0)
                goto out;
#ifdef MAC
        error = mac_mount_check_stat(td->td_ucred, mp);
        if (error != 0)
                goto out;
#endif
        /*
         * Set these in case the underlying filesystem fails to do so.
         */
        sp = &mp->mnt_stat;
        sp->f_version = STATFS_VERSION;
        sp->f_namemax = NAME_MAX;
        sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
        error = VFS_STATFS(mp, sp);
        if (error == 0)
                *buf = *sp;
out:
        vfs_unbusy(mp);
        return (error);
}

int
kern_posix_fallocate(struct thread *td, int fd, off_t offset, off_t len)
{
        struct file *fp;
        struct mount *mp;
        struct vnode *vp;
        cap_rights_t rights;
        off_t olen, ooffset;
        int error;
#ifdef AUDIT
        int audited_vnode1 = 0;
#endif

        AUDIT_ARG_FD(fd);
        if (offset < 0 || len <= 0)
                return (EINVAL);
        /* Check for wrap. */
        if (offset > OFF_MAX - len)
                return (EFBIG);
        AUDIT_ARG_FD(fd);
        error = fget(td, fd, cap_rights_init(&rights, CAP_PWRITE), &fp);
        if (error != 0)
                return (error);
        AUDIT_ARG_FILE(td->td_proc, fp);
        if ((fp->f_ops->fo_flags & DFLAG_SEEKABLE) == 0) {
                error = ESPIPE;
                goto out;
        }
        if ((fp->f_flag & FWRITE) == 0) {
                error = EBADF;
                goto out;
        }
        if (fp->f_type != DTYPE_VNODE) {
                error = ENODEV;
                goto out;
        }
        vp = fp->f_vnode;
        if (vp->v_type != VREG) {
                error = ENODEV;
                goto out;
        }

        /* Allocating blocks may take a long time, so iterate. */
        for (;;) {
                olen = len;
                ooffset = offset;

                bwillwrite();
                mp = NULL;
                error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
                if (error != 0)
                        break;
                error = vn_lock(vp, LK_EXCLUSIVE);
                if (error != 0) {
                        vn_finished_write(mp);
                        break;
                }
#ifdef AUDIT
                if (!audited_vnode1) {
                        AUDIT_ARG_VNODE1(vp);
                        audited_vnode1 = 1;
                }
#endif
#ifdef MAC
                error = mac_vnode_check_write(td->td_ucred, fp->f_cred, vp);
                if (error == 0)
#endif
                        error = VOP_ALLOCATE(vp, &offset, &len);
                VOP_UNLOCK(vp, 0);
                vn_finished_write(mp);

                if (olen + ooffset != offset + len) {
                        panic("offset + len changed from %jx/%jx to %jx/%jx",
                            ooffset, olen, offset, len);
                }
                if (error != 0 || len == 0)
                        break;
                KASSERT(olen > len, ("Iteration did not make progress?"));
                maybe_yield();
        }
 out:
        fdrop(fp, td);
        return (error);
}

int
sys_posix_fallocate(struct thread *td, struct posix_fallocate_args *uap)
{
        int error;

        error = kern_posix_fallocate(td, uap->fd, uap->offset, uap->len);
        return (kern_posix_error(td, error));
}

/*
 * Unlike madvise(2), we do not make a best effort to remember every
 * possible caching hint.  Instead, we remember the last setting with
 * the exception that we will allow POSIX_FADV_NORMAL to adjust the
 * region of any current setting.
 */
int
kern_posix_fadvise(struct thread *td, int fd, off_t offset, off_t len,
    int advice)
{
        struct fadvise_info *fa, *new;
        struct file *fp;
        struct vnode *vp;
        cap_rights_t rights;
        off_t end;
        int error;

        if (offset < 0 || len < 0 || offset > OFF_MAX - len)
                return (EINVAL);
        AUDIT_ARG_VALUE(advice);
        switch (advice) {
        case POSIX_FADV_SEQUENTIAL:
        case POSIX_FADV_RANDOM:
        case POSIX_FADV_NOREUSE:
                new = malloc(sizeof(*fa), M_FADVISE, M_WAITOK);
                break;
        case POSIX_FADV_NORMAL:
        case POSIX_FADV_WILLNEED:
        case POSIX_FADV_DONTNEED:
                new = NULL;
                break;
        default:
                return (EINVAL);
        }
        /* XXX: CAP_POSIX_FADVISE? */
        AUDIT_ARG_FD(fd);
        error = fget(td, fd, cap_rights_init(&rights), &fp);
        if (error != 0)
                goto out;
        AUDIT_ARG_FILE(td->td_proc, fp);
        if ((fp->f_ops->fo_flags & DFLAG_SEEKABLE) == 0) {
                error = ESPIPE;
                goto out;
        }
        if (fp->f_type != DTYPE_VNODE) {
                error = ENODEV;
                goto out;
        }
        vp = fp->f_vnode;
        if (vp->v_type != VREG) {
                error = ENODEV;
                goto out;
        }
        if (len == 0)
                end = OFF_MAX;
        else
                end = offset + len - 1;
        switch (advice) {
        case POSIX_FADV_SEQUENTIAL:
        case POSIX_FADV_RANDOM:
        case POSIX_FADV_NOREUSE:
                /*
                 * Try to merge any existing non-standard region with
                 * this new region if possible, otherwise create a new
                 * non-standard region for this request.
                 */
                mtx_pool_lock(mtxpool_sleep, fp);
                fa = fp->f_advice;
                if (fa != NULL && fa->fa_advice == advice &&
                    ((fa->fa_start <= end && fa->fa_end >= offset) ||
                    (end != OFF_MAX && fa->fa_start == end + 1) ||
                    (fa->fa_end != OFF_MAX && fa->fa_end + 1 == offset))) {
                        if (offset < fa->fa_start)
                                fa->fa_start = offset;
                        if (end > fa->fa_end)
                                fa->fa_end = end;
                } else {
                        new->fa_advice = advice;
                        new->fa_start = offset;
                        new->fa_end = end;
                        fp->f_advice = new;
                        new = fa;
                }
                mtx_pool_unlock(mtxpool_sleep, fp);
                break;
        case POSIX_FADV_NORMAL:
                /*
                 * If a the "normal" region overlaps with an existing
                 * non-standard region, trim or remove the
                 * non-standard region.
                 */
                mtx_pool_lock(mtxpool_sleep, fp);
                fa = fp->f_advice;
                if (fa != NULL) {
                        if (offset <= fa->fa_start && end >= fa->fa_end) {
                                new = fa;
                                fp->f_advice = NULL;
                        } else if (offset <= fa->fa_start &&
                            end >= fa->fa_start)
                                fa->fa_start = end + 1;
                        else if (offset <= fa->fa_end && end >= fa->fa_end)
                                fa->fa_end = offset - 1;
                        else if (offset >= fa->fa_start && end <= fa->fa_end) {
                                /*
                                 * If the "normal" region is a middle
                                 * portion of the existing
                                 * non-standard region, just remove
                                 * the whole thing rather than picking
                                 * one side or the other to
                                 * preserve.
                                 */
                                new = fa;
                                fp->f_advice = NULL;
                        }
                }
                mtx_pool_unlock(mtxpool_sleep, fp);
                break;
        case POSIX_FADV_WILLNEED:
        case POSIX_FADV_DONTNEED:
                error = VOP_ADVISE(vp, offset, end, advice);
                break;
        }
out:
        if (fp != NULL)
                fdrop(fp, td);
        free(new, M_FADVISE);
        return (error);
}

int
sys_posix_fadvise(struct thread *td, struct posix_fadvise_args *uap)
{
        int error;

        error = kern_posix_fadvise(td, uap->fd, uap->offset, uap->len,
            uap->advice);
        return (kern_posix_error(td, error));
}