xref: /freebsd-13.1/sys/kern/vfs_syscalls.c (revision 821467b5)

/*-
 * 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_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 <fs/devfs/devfs.h>

#include <ufs/ufs/quota.h>

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

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);
static int kern_fhlinkat(struct thread *td, int fd, const char *path,
    enum uio_seg pathseg, fhandle_t *fhp);
static int kern_readlink_vp(struct vnode *vp, char *buf, enum uio_seg bufseg,
    size_t count, struct thread *td);
static int kern_linkat_vp(struct thread *td, struct vnode *vp, int fd,
    const char *path, enum uio_seg segflag);

static uint64_t
at2cnpflags(u_int at_flags, u_int mask)
{
	u_int64_t res;

	MPASS((at_flags & (AT_SYMLINK_FOLLOW | AT_SYMLINK_NOFOLLOW)) !=
	    (AT_SYMLINK_FOLLOW | AT_SYMLINK_NOFOLLOW));

	res = 0;
	at_flags &= mask;
	if ((at_flags & AT_RESOLVE_BENEATH) != 0)
		res |= RBENEATH;
	if ((at_flags & AT_SYMLINK_FOLLOW) != 0)
		res |= FOLLOW;
	/* NOFOLLOW is pseudo flag */
	if ((mask & AT_SYMLINK_NOFOLLOW) != 0) {
		res |= (at_flags & AT_SYMLINK_NOFOLLOW) != 0 ? NOFOLLOW :
		    FOLLOW;
	}
	if ((mask & AT_EMPTY_PATH) != 0 && (at_flags & AT_EMPTY_PATH) != 0)
		res |= EMPTYPATH;
	return (res);
}

int
kern_sync(struct thread *td)
{
	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_periodic(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);
}

/*
 * 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)
{

	return (kern_sync(td));
}

/*
 * 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);
	if (error != 0) {
		vfs_rel(mp);
		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 &&
	    (uap->cmd >> SUBCMDSHIFT) != Q_QUOTAOFF)
		vfs_unbusy(mp);
	vfs_rel(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)
{
	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
	error = VFS_STATFS(mp, buf);
	if (error != 0)
		goto out;
	if (priv_check_cred_vfs_generation(td->td_ucred)) {
		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, const char *path, enum uio_seg pathseg,
    struct statfs *buf)
{
	struct mount *mp;
	struct nameidata nd;
	int error;

	NDINIT(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path, td);
	error = namei(&nd);
	if (error != 0)
		return (error);
	mp = vfs_ref_from_vp(nd.ni_vp);
	NDFREE_NOTHING(&nd);
	vrele(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;
	int error;

	AUDIT_ARG_FD(fd);
	error = getvnode_path(td, fd, &cap_fstatfs_rights, &fp);
	if (error != 0)
		return (error);
	vp = fp->f_vnode;
#ifdef AUDIT
	if (AUDITING_TD(td)) {
		vn_lock(vp, LK_SHARED | LK_RETRY);
		AUDIT_ARG_VNODE1(vp);
		VOP_UNLOCK(vp);
	}
#endif
	mp = vfs_ref_from_vp(vp);
	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;

	/*
	 * If there is no target buffer they only want the count.
	 *
	 * This could be TAILQ_FOREACH but it is open-coded to match the original
	 * code below.
	 */
	if (sfsp == NULL) {
		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
			count++;
			nmp = TAILQ_NEXT(mp, mnt_list);
		}
		mtx_unlock(&mountlist_mtx);
		*countp = count;
		return (0);
	}

	/*
	 * They want the entire thing.
	 *
	 * Short-circuit the corner case of no room for anything, avoids
	 * relocking below.
	 */
	if (maxcount < 1) {
		goto out;
	}

	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;
			}
		}
		sp = &mp->mnt_stat;
		/*
		 * 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_cred_vfs_generation(td->td_ucred)) {
			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++;

		if (count == maxcount) {
			vfs_unbusy(mp);
			goto out;
		}

		mtx_lock(&mountlist_mtx);
		nmp = TAILQ_NEXT(mp, mnt_list);
		vfs_unbusy(mp);
	}
	mtx_unlock(&mountlist_mtx);
out:
	*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;
	int error;

	AUDIT_ARG_FD(uap->fd);
	error = getvnode_path(td, uap->fd, &cap_fchdir_rights,
	    &fp);
	if (error != 0)
		return (error);
	vp = fp->f_vnode;
	vref(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);
	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, const 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_NOTHING(&nd);
		return (error);
	}
	VOP_UNLOCK(nd.ni_vp);
	NDFREE_NOTHING(&nd);
	pwd_chdir(td, nd.ni_vp);
	return (0);
}

static int unprivileged_chroot = 0;
SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_chroot, CTLFLAG_RW,
    &unprivileged_chroot, 0,
    "Unprivileged processes can use chroot(2)");
/*
 * 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;
	struct proc *p;
	int error;

	error = priv_check(td, PRIV_VFS_CHROOT);
	if (error != 0) {
		p = td->td_proc;
		PROC_LOCK(p);
		if (unprivileged_chroot == 0 ||
		    (p->p_flag2 & P2_NO_NEW_PRIVS) == 0) {
			PROC_UNLOCK(p);
			return (error);
		}
		PROC_UNLOCK(p);
	}
	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);
	error = pwd_chroot(td, nd.ni_vp);
	vrele(nd.ni_vp);
	NDFREE_NOTHING(&nd);
	return (error);
e_vunlock:
	vput(nd.ni_vp);
error:
	NDFREE_NOTHING(&nd);
	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_one(rightsp, CAP_FEXECVE);
		if (flags & O_PATH)
			return;
	} else {
		switch ((flags & O_ACCMODE)) {
		case O_RDONLY:
			cap_rights_set_one(rightsp, CAP_READ);
			break;
		case O_RDWR:
			cap_rights_set_one(rightsp, CAP_READ);
			/* FALLTHROUGH */
		case O_WRONLY:
			cap_rights_set_one(rightsp, CAP_WRITE);
			if (!(flags & (O_APPEND | O_TRUNC)))
				cap_rights_set_one(rightsp, CAP_SEEK);
			break;
		}
	}

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

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

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

	if (flags & (O_EXLOCK | O_SHLOCK))
		cap_rights_set_one(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, const char *path, enum uio_seg pathseg,
    int flags, int mode)
{
	struct proc *p = td->td_proc;
	struct filedesc *fdp;
	struct pwddesc *pdp;
	struct file *fp;
	struct vnode *vp;
	struct nameidata nd;
	cap_rights_t rights;
	int cmode, error, indx;

	indx = -1;
	fdp = p->p_fd;
	pdp = p->p_pd;

	AUDIT_ARG_FFLAGS(flags);
	AUDIT_ARG_MODE(mode);
	cap_rights_init_one(&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.  On the other hand, for O_PATH any mode
	 * except O_EXEC is ignored.
	 */
	if ((flags & O_PATH) != 0) {
		flags &= ~(O_CREAT | O_ACCMODE);
	} else if ((flags & O_EXEC) != 0) {
		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 used by finstall_refed() below.
	 */
	error = falloc_noinstall(td, &fp);
	if (error != 0)
		return (error);
	/* Set the flags early so the finit in devfs can pick them up. */
	fp->f_flag = flags & FMASK;
	cmode = ((mode & ~pdp->pd_cmask) & ALLPERMS) & ~S_ISTXT;
	NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | AUDITVNODE1 | WANTIOCTLCAPS,
	    pathseg, path, fd, &rights, td);
	td->td_dupfd = -1;		/* XXX check for fdopen */
	error = vn_open_cred(&nd, &flags, cmode, VN_OPEN_WANTIOCTLCAPS,
	    td->td_ucred, 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) {
			MPASS((flags & O_PATH) == 0);
			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_resflags & NIRES_STRICTREL) == 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 || (flags & O_PATH) != 0,
		    ("Unexpected fifo fp %p vp %p", fp, vp));
		if ((flags & O_PATH) != 0) {
			finit(fp, (flags & FMASK) | (fp->f_flag & FKQALLOWED),
			    DTYPE_VNODE, NULL, &path_fileops);
		} else {
			finit_vnode(fp, flags, NULL, &vnops);
		}
	}

	VOP_UNLOCK(vp);
	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_resflags & NIRES_STRICTREL) != 0)
			fcaps = &nd.ni_filecaps;
		else
#endif
			fcaps = NULL;
		error = finstall_refed(td, fp, &indx, flags, fcaps);
		/* On success finstall_refed() consumes fcaps. */
		if (error != 0) {
			goto bad;
		}
	} else {
		NDFREE_IOCTLCAPS(&nd);
		falloc_abort(td, fp);
	}

	td->td_retval[0] = indx;
	return (0);
bad:
	KASSERT(indx == -1, ("indx=%d, should be -1", indx));
	NDFREE_IOCTLCAPS(&nd);
	falloc_abort(td, fp);
	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, const char *path, enum uio_seg pathseg,
    int mode, dev_t dev)
{
	struct vnode *vp;
	struct mount *mp;
	struct vattr vattr;
	struct nameidata nd;
	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);
	NDPREINIT(&nd);
restart:
	bwillwrite();
	NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | SAVENAME | AUDITVNODE1 |
	    NOCACHE, pathseg, path, fd, &cap_mknodat_rights,
	    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_pd->pd_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);
		}
	}
	VOP_VPUT_PAIR(nd.ni_dvp, error == 0 && !whiteout ? &nd.ni_vp : NULL,
	    true);
	vn_finished_write(mp);
	NDFREE(&nd, NDF_ONLY_PNBUF);
	if (error == ERELOOKUP)
		goto restart;
	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, const char *path,
    enum uio_seg pathseg, int mode)
{
	struct mount *mp;
	struct vattr vattr;
	struct nameidata nd;
	int error;

	AUDIT_ARG_MODE(mode);
	NDPREINIT(&nd);
restart:
	bwillwrite();
	NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | SAVENAME | AUDITVNODE1 |
	    NOCACHE, pathseg, path, fd, &cap_mkfifoat_rights,
	    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_pd->pd_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);
#ifdef MAC
out:
#endif
	VOP_VPUT_PAIR(nd.ni_dvp, error == 0 ? &nd.ni_vp : NULL, true);
	vn_finished_write(mp);
	NDFREE(&nd, NDF_ONLY_PNBUF);
	if (error == ERELOOKUP)
		goto restart;
	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 | AT_RESOLVE_BENEATH |
	    AT_EMPTY_PATH)) != 0)
		return (EINVAL);

	return (kern_linkat(td, uap->fd1, uap->fd2, uap->path1, uap->path2,
	    UIO_USERSPACE, at2cnpflags(flag, AT_SYMLINK_FOLLOW |
	    AT_RESOLVE_BENEATH | AT_EMPTY_PATH)));
}

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);
		if (error != 0)
			return (error);
	}

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

	return (0);
}

int
kern_linkat(struct thread *td, int fd1, int fd2, const char *path1,
    const char *path2, enum uio_seg segflag, int follow)
{
	struct nameidata nd;
	int error;

	NDPREINIT(&nd);
	do {
		bwillwrite();
		NDINIT_ATRIGHTS(&nd, LOOKUP, follow | AUDITVNODE1, segflag,
		    path1, fd1, &cap_linkat_source_rights, td);
		if ((error = namei(&nd)) != 0)
			return (error);
		NDFREE(&nd, NDF_ONLY_PNBUF);
		if ((nd.ni_resflags & NIRES_EMPTYPATH) != 0) {
			error = priv_check(td, PRIV_VFS_FHOPEN);
			if (error != 0) {
				vrele(nd.ni_vp);
				return (error);
			}
		}
		error = kern_linkat_vp(td, nd.ni_vp, fd2, path2, segflag);
	} while (error ==  EAGAIN || error == ERELOOKUP);
	return (error);
}

static int
kern_linkat_vp(struct thread *td, struct vnode *vp, int fd, const char *path,
    enum uio_seg segflag)
{
	struct nameidata nd;
	struct mount *mp;
	int error;

	if (vp->v_type == VDIR) {
		vrele(vp);
		return (EPERM);		/* POSIX */
	}
	NDINIT_ATRIGHTS(&nd, CREATE,
	    LOCKPARENT | SAVENAME | AUDITVNODE2 | NOCACHE, segflag, path, fd,
	    &cap_linkat_target_rights, 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);
				return (EAGAIN);
			}
			error = VOP_LINK(nd.ni_dvp, vp, &nd.ni_cnd);
			VOP_VPUT_PAIR(nd.ni_dvp, &vp, true);
			vn_finished_write(mp);
			NDFREE(&nd, NDF_ONLY_PNBUF);
			vp = NULL;
		} else {
			vput(nd.ni_dvp);
			NDFREE(&nd, NDF_ONLY_PNBUF);
			vrele(vp);
			return (EAGAIN);
		}
	}
	if (vp != NULL)
		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, const char *path1, int fd, const char *path2,
    enum uio_seg segflg)
{
	struct mount *mp;
	struct vattr vattr;
	const char *syspath;
	char *tmppath;
	struct nameidata nd;
	int error;

	if (segflg == UIO_SYSSPACE) {
		syspath = path1;
	} else {
		tmppath = uma_zalloc(namei_zone, M_WAITOK);
		if ((error = copyinstr(path1, tmppath, MAXPATHLEN, NULL)) != 0)
			goto out;
		syspath = tmppath;
	}
	AUDIT_ARG_TEXT(syspath);
	NDPREINIT(&nd);
restart:
	bwillwrite();
	NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | SAVENAME | AUDITVNODE1 |
	    NOCACHE, segflg, path2, fd, &cap_symlinkat_rights,
	    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);
		nd.ni_vp = NULL;
		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_pd->pd_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);
#ifdef MAC
out2:
#endif
	VOP_VPUT_PAIR(nd.ni_dvp, error == 0 ? &nd.ni_vp : NULL, true);
	vn_finished_write(mp);
	NDFREE(&nd, NDF_ONLY_PNBUF);
	if (error == ERELOOKUP)
		goto restart;
out:
	if (segflg != UIO_SYSSPACE)
		uma_zfree(namei_zone, tmppath);
	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;

	NDPREINIT(&nd);
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);
	if (error == ERELOOKUP)
		goto restart;
	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_funlinkat(td, AT_FDCWD, uap->path, FD_NONE, UIO_USERSPACE,
	    0, 0));
}

static int
kern_funlinkat_ex(struct thread *td, int dfd, const char *path, int fd,
    int flag, enum uio_seg pathseg, ino_t oldinum)
{

	if ((flag & ~(AT_REMOVEDIR | AT_RESOLVE_BENEATH)) != 0)
		return (EINVAL);

	if ((flag & AT_REMOVEDIR) != 0)
		return (kern_frmdirat(td, dfd, path, fd, UIO_USERSPACE, 0));

	return (kern_funlinkat(td, dfd, path, fd, UIO_USERSPACE, 0, 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)
{

	return (kern_funlinkat_ex(td, uap->fd, uap->path, FD_NONE, uap->flag,
	    UIO_USERSPACE, 0));
}

#ifndef _SYS_SYSPROTO_H_
struct funlinkat_args {
	int		dfd;
	const char	*path;
	int		fd;
	int		flag;
};
#endif
int
sys_funlinkat(struct thread *td, struct funlinkat_args *uap)
{

	return (kern_funlinkat_ex(td, uap->dfd, uap->path, uap->fd, uap->flag,
	    UIO_USERSPACE, 0));
}

int
kern_funlinkat(struct thread *td, int dfd, const char *path, int fd,
    enum uio_seg pathseg, int flag, ino_t oldinum)
{
	struct mount *mp;
	struct file *fp;
	struct vnode *vp;
	struct nameidata nd;
	struct stat sb;
	int error;

	fp = NULL;
	if (fd != FD_NONE) {
		error = getvnode_path(td, fd, &cap_no_rights, &fp);
		if (error != 0)
			return (error);
	}

	NDPREINIT(&nd);
restart:
	bwillwrite();
	NDINIT_ATRIGHTS(&nd, DELETE, LOCKPARENT | LOCKLEAF | AUDITVNODE1 |
	    at2cnpflags(flag, AT_RESOLVE_BENEATH),
	    pathseg, path, dfd, &cap_unlinkat_rights, td);
	if ((error = namei(&nd)) != 0) {
		if (error == EINVAL)
			error = EPERM;
		goto fdout;
	}
	vp = nd.ni_vp;
	if (vp->v_type == VDIR && oldinum == 0) {
		error = EPERM;		/* POSIX */
	} else if (oldinum != 0 &&
	    ((error = VOP_STAT(vp, &sb, td->td_ucred, NOCRED, td)) == 0) &&
	    sb.st_ino != oldinum) {
		error = EIDRM;	/* Identifier removed */
	} else if (fp != NULL && fp->f_vnode != vp) {
		if (VN_IS_DOOMED(fp->f_vnode))
			error = EBADF;
		else
			error = EDEADLK;
	} 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) {
				goto fdout;
			}
			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);
	if (error == ERELOOKUP)
		goto restart;
fdout:
	if (fp != NULL)
		fdrop(fp, td);
	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;
	int error;

	AUDIT_ARG_FD(fd);
	error = fget(td, fd, &cap_seek_rights, &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, const char *path,
    enum uio_seg pathseg, int flag, int amode)
{
	struct ucred *cred, *usecred;
	struct vnode *vp;
	struct nameidata nd;
	int error;

	if ((flag & ~(AT_EACCESS | AT_RESOLVE_BENEATH | AT_EMPTY_PATH)) != 0)
		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 | at2cnpflags(flag, AT_RESOLVE_BENEATH |
	    AT_EMPTY_PATH), pathseg, path, fd, &cap_fstat_rights, td);
	if ((error = namei(&nd)) != 0)
		goto out;
	vp = nd.ni_vp;

	error = vn_access(vp, amode, usecred, td);
	NDFREE_NOTHING(&nd);
	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.
 * XXX: many values are blindly truncated.
 */
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;
	ost->st_size = MIN(st->st_size, INT32_MAX);
	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 device, file or inode number, or link count");

int
freebsd11_cvtstat(struct stat *st, struct freebsd11_stat *ost)
{

	ost->st_dev = st->st_dev;
	if (ost->st_dev != st->st_dev) {
		switch (ino64_trunc_error) {
		default:
			/*
			 * Since dev_t is almost raw, don't clamp to the
			 * maximum for case 2, but ignore the error.
			 */
			break;
		case 1:
			return (EOVERFLOW);
		}
	}
	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;
	if (ost->st_rdev != st->st_rdev) {
		switch (ino64_trunc_error) {
		default:
			break;
		case 1:
			return (EOVERFLOW);
		}
	}
	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, const char *path,
    enum uio_seg pathseg, struct stat *sbp,
    void (*hook)(struct vnode *vp, struct stat *sbp))
{
	struct nameidata nd;
	int error;

	if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_RESOLVE_BENEATH |
	    AT_EMPTY_PATH)) != 0)
		return (EINVAL);

	NDINIT_ATRIGHTS(&nd, LOOKUP, at2cnpflags(flag, AT_RESOLVE_BENEATH |
	    AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH) | LOCKSHARED | LOCKLEAF |
	    AUDITVNODE1, pathseg, path, fd, &cap_fstat_rights, td);

	if ((error = namei(&nd)) != 0) {
		if (error == ENOTDIR &&
		    (nd.ni_resflags & NIRES_EMPTYPATH) != 0)
			error = kern_fstat(td, fd, sbp);
		return (error);
	}
	error = VOP_STAT(nd.ni_vp, sbp, td->td_ucred, NOCRED, td);
	if (error == 0) {
		if (__predict_false(hook != NULL))
			hook(nd.ni_vp, sbp);
	}
	NDFREE_NOTHING(&nd);
	vput(nd.ni_vp);
#ifdef __STAT_TIME_T_EXT
	sbp->st_atim_ext = 0;
	sbp->st_mtim_ext = 0;
	sbp->st_ctim_ext = 0;
	sbp->st_btim_ext = 0;
#endif
#ifdef KTRACE
	if (KTRPOINT(td, KTR_STRUCT))
		ktrstat_error(sbp, error);
#endif
	return (error);
}

#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, const 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_NOTHING(&nd);

	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, const char *path,
    enum uio_seg pathseg, char *buf, enum uio_seg bufseg, size_t count)
{
	struct vnode *vp;
	struct nameidata nd;
	int error;

	if (count > IOSIZE_MAX)
		return (EINVAL);

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

	if ((error = namei(&nd)) != 0)
		return (error);
	NDFREE_NOTHING(&nd);
	vp = nd.ni_vp;

	error = kern_readlink_vp(vp, buf, bufseg, count, td);
	vput(vp);

	return (error);
}

/*
 * Helper function to readlink from a vnode
 */
static int
kern_readlink_vp(struct vnode *vp, char *buf, enum uio_seg bufseg, size_t count,
    struct thread *td)
{
	struct iovec aiov;
	struct uio auio;
	int error;

	ASSERT_VOP_LOCKED(vp, "kern_readlink_vp(): vp not locked");
#ifdef MAC
	error = mac_vnode_check_readlink(td->td_ucred, vp);
	if (error != 0)
		return (error);
#endif
	if (vp->v_type != VLNK && (vp->v_vflag & VV_READLINK) == 0)
		return (EINVAL);

	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;
	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);
	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)
{

	if ((uap->atflag & ~(AT_SYMLINK_NOFOLLOW | AT_RESOLVE_BENEATH |
	    AT_EMPTY_PATH)) != 0)
		return (EINVAL);

	return (kern_chflagsat(td, uap->fd, uap->path, UIO_USERSPACE,
	    uap->flags, uap->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;
	int error;

	AUDIT_ARG_FFLAGS(flags);
	NDINIT_ATRIGHTS(&nd, LOOKUP, at2cnpflags(atflag, AT_SYMLINK_NOFOLLOW |
	    AT_RESOLVE_BENEATH | AT_EMPTY_PATH) | AUDITVNODE1, pathseg, path,
	    fd, &cap_fchflags_rights, td);
	if ((error = namei(&nd)) != 0)
		return (error);
	NDFREE_NOTHING(&nd);
	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;
	int error;

	AUDIT_ARG_FD(uap->fd);
	AUDIT_ARG_FFLAGS(uap->flags);
	error = getvnode(td, uap->fd, &cap_fchflags_rights,
	    &fp);
	if (error != 0)
		return (error);
#ifdef AUDIT
	if (AUDITING_TD(td)) {
		vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
		AUDIT_ARG_VNODE1(fp->f_vnode);
		VOP_UNLOCK(fp->f_vnode);
	}
#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);
	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)
{

	if ((uap->flag & ~(AT_SYMLINK_NOFOLLOW | AT_RESOLVE_BENEATH |
	    AT_EMPTY_PATH)) != 0)
		return (EINVAL);

	return (kern_fchmodat(td, uap->fd, uap->path, UIO_USERSPACE,
	    uap->mode, uap->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, const char *path,
    enum uio_seg pathseg, mode_t mode, int flag)
{
	struct nameidata nd;
	int error;

	AUDIT_ARG_MODE(mode);
	NDINIT_ATRIGHTS(&nd, LOOKUP, at2cnpflags(flag, AT_SYMLINK_NOFOLLOW |
	    AT_RESOLVE_BENEATH | AT_EMPTY_PATH) | AUDITVNODE1, pathseg, path,
	    fd, &cap_fchmod_rights, td);
	if ((error = namei(&nd)) != 0)
		return (error);
	NDFREE_NOTHING(&nd);
	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;
	int error;

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

	error = fget(td, uap->fd, &cap_fchmod_rights, &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);
	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)
{

	if ((uap->flag & ~(AT_SYMLINK_NOFOLLOW | AT_RESOLVE_BENEATH |
	    AT_EMPTY_PATH)) != 0)
		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, const char *path,
    enum uio_seg pathseg, int uid, int gid, int flag)
{
	struct nameidata nd;
	int error;

	AUDIT_ARG_OWNER(uid, gid);
	NDINIT_ATRIGHTS(&nd, LOOKUP, at2cnpflags(flag, AT_SYMLINK_NOFOLLOW |
	    AT_RESOLVE_BENEATH | AT_EMPTY_PATH) | AUDITVNODE1, pathseg, path,
	    fd, &cap_fchown_rights, td);

	if ((error = namei(&nd)) != 0)
		return (error);
	NDFREE_NOTHING(&nd);
	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;
	int error;

	AUDIT_ARG_FD(uap->fd);
	AUDIT_ARG_OWNER(uap->uid, uap->gid);
	error = fget(td, uap->fd, &cap_fchown_rights, &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;
	bool setbirthtime;

	setbirthtime = false;
	vattr.va_birthtime.tv_sec = VNOVAL;
	vattr.va_birthtime.tv_nsec = 0;

	if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
		return (error);
	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
	if (numtimes < 3 && VOP_GETATTR(vp, &vattr, td->td_ucred) == 0 &&
	    timespeccmp(&ts[1], &vattr.va_birthtime, < ))
		setbirthtime = true;
	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);
	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, const char *path,
    enum uio_seg pathseg, struct timeval *tptr, enum uio_seg tptrseg)
{
	struct nameidata nd;
	struct timespec ts[2];
	int error;

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

	if ((error = namei(&nd)) != 0)
		return (error);
	NDFREE_NOTHING(&nd);
	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, const 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_NOTHING(&nd);
	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;
	int error;

	AUDIT_ARG_FD(fd);
	error = getutimes(tptr, tptrseg, ts);
	if (error != 0)
		return (error);
	error = getvnode(td, fd, &cap_futimes_rights, &fp);
	if (error != 0)
		return (error);
#ifdef AUDIT
	if (AUDITING_TD(td)) {
		vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
		AUDIT_ARG_VNODE1(fp->f_vnode);
		VOP_UNLOCK(fp->f_vnode);
	}
#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;
	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_futimes_rights, &fp);
	if (error != 0)
		return (error);
#ifdef AUDIT
	if (AUDITING_TD(td)) {
		vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
		AUDIT_ARG_VNODE1(fp->f_vnode);
		VOP_UNLOCK(fp->f_vnode);
	}
#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, const char *path,
    enum uio_seg pathseg, struct timespec *tptr, enum uio_seg tptrseg,
    int flag)
{
	struct nameidata nd;
	struct timespec ts[2];
	int error, flags;

	if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_RESOLVE_BENEATH |
	    AT_EMPTY_PATH)) != 0)
		return (EINVAL);

	if ((error = getutimens(tptr, tptrseg, ts, &flags)) != 0)
		return (error);
	NDINIT_ATRIGHTS(&nd, LOOKUP, at2cnpflags(flag, AT_SYMLINK_NOFOLLOW |
	    AT_RESOLVE_BENEATH | AT_EMPTY_PATH) | AUDITVNODE1,
	    pathseg, path, fd, &cap_futimes_rights, 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_NOTHING(&nd);
	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, const 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);
	NDPREINIT(&nd);
retry:
	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);
	vn_finished_write(mp);
	vn_rangelock_unlock(vp, rl_cookie);
	vrele(vp);
	if (error == ERELOOKUP)
		goto retry;
	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;
	int error;

	AUDIT_ARG_FD(fd);
	error = getvnode(td, fd, &cap_fsync_rights, &fp);
	if (error != 0)
		return (error);
	vp = fp->f_vnode;
#if 0
	if (!fullsync)
		/* XXXKIB: compete outstanding aio writes */;
#endif
retry:
	error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
	if (error != 0)
		goto drop;
	vn_lock(vp, vn_lktype_write(mp, vp) | 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);
	vn_finished_write(mp);
	if (error == ERELOOKUP)
		goto retry;
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));
}

#ifdef MAC
static int
kern_renameat_mac(struct thread *td, int oldfd, const char *old, int newfd,
    const char *new, enum uio_seg pathseg, struct nameidata *fromnd)
{
	int error;

	NDINIT_ATRIGHTS(fromnd, DELETE, LOCKPARENT | LOCKLEAF | SAVESTART |
	    AUDITVNODE1, pathseg, old, oldfd, &cap_renameat_source_rights, td);
	if ((error = namei(fromnd)) != 0)
		return (error);
	error = mac_vnode_check_rename_from(td->td_ucred, fromnd->ni_dvp,
	    fromnd->ni_vp, &fromnd->ni_cnd);
	VOP_UNLOCK(fromnd->ni_dvp);
	if (fromnd->ni_dvp != fromnd->ni_vp)
		VOP_UNLOCK(fromnd->ni_vp);
	if (error != 0) {
		NDFREE(fromnd, NDF_ONLY_PNBUF);
		vrele(fromnd->ni_dvp);
		vrele(fromnd->ni_vp);
		if (fromnd->ni_startdir)
			vrele(fromnd->ni_startdir);
	}
	return (error);
}
#endif

int
kern_renameat(struct thread *td, int oldfd, const char *old, int newfd,
    const char *new, enum uio_seg pathseg)
{
	struct mount *mp = NULL;
	struct vnode *tvp, *fvp, *tdvp;
	struct nameidata fromnd, tond;
	u_int64_t tondflags;
	int error;

again:
	bwillwrite();
#ifdef MAC
	if (mac_vnode_check_rename_from_enabled()) {
		error = kern_renameat_mac(td, oldfd, old, newfd, new, pathseg,
		    &fromnd);
		if (error != 0)
			return (error);
	} else {
#endif
	NDINIT_ATRIGHTS(&fromnd, DELETE, WANTPARENT | SAVESTART | AUDITVNODE1,
	    pathseg, old, oldfd, &cap_renameat_source_rights, td);
	if ((error = namei(&fromnd)) != 0)
		return (error);
#ifdef MAC
	}
#endif
	fvp = fromnd.ni_vp;
	tondflags = LOCKPARENT | LOCKLEAF | NOCACHE | SAVESTART | AUDITVNODE2;
	if (fromnd.ni_vp->v_type == VDIR)
		tondflags |= WILLBEDIR;
	NDINIT_ATRIGHTS(&tond, RENAME, tondflags, pathseg, new, newfd,
	    &cap_renameat_target_rights, td);
	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 && (tond.ni_resflags & NIRES_ABS) == 0) {
			/*
			 * If the target already exists we require CAP_UNLINKAT
			 * from 'newfd', when newfd was used for the lookup.
			 */
			error = cap_check(&tond.ni_filecaps.fc_rights,
			    &cap_unlinkat_rights);
			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 = ERESTART;
#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 == ERESTART)
		return (0);
	if (error == ERELOOKUP)
		goto again;
	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, const char *path, enum uio_seg segflg,
    int mode)
{
	struct mount *mp;
	struct vattr vattr;
	struct nameidata nd;
	int error;

	AUDIT_ARG_MODE(mode);
	NDPREINIT(&nd);
restart:
	bwillwrite();
	NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | SAVENAME | AUDITVNODE1 |
	    NC_NOMAKEENTRY | NC_KEEPPOSENTRY | FAILIFEXISTS | WILLBEDIR,
	    segflg, path, fd, &cap_mkdirat_rights, td);
	if ((error = namei(&nd)) != 0)
		return (error);
	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_pd->pd_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);
	VOP_VPUT_PAIR(nd.ni_dvp, error == 0 ? &nd.ni_vp : NULL, true);
	vn_finished_write(mp);
	if (error == ERELOOKUP)
		goto restart;
	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_frmdirat(td, AT_FDCWD, uap->path, FD_NONE, UIO_USERSPACE,
	    0));
}

int
kern_frmdirat(struct thread *td, int dfd, const char *path, int fd,
    enum uio_seg pathseg, int flag)
{
	struct mount *mp;
	struct vnode *vp;
	struct file *fp;
	struct nameidata nd;
	cap_rights_t rights;
	int error;

	fp = NULL;
	if (fd != FD_NONE) {
		error = getvnode(td, fd, cap_rights_init_one(&rights,
		    CAP_LOOKUP), &fp);
		if (error != 0)
			return (error);
	}

	NDPREINIT(&nd);
restart:
	bwillwrite();
	NDINIT_ATRIGHTS(&nd, DELETE, LOCKPARENT | LOCKLEAF | AUDITVNODE1 |
	    at2cnpflags(flag, AT_RESOLVE_BENEATH),
	    pathseg, path, dfd, &cap_unlinkat_rights, td);
	if ((error = namei(&nd)) != 0)
		goto fdout;
	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;
	}

	if (fp != NULL && fp->f_vnode != vp) {
		if (VN_IS_DOOMED(fp->f_vnode))
			error = EBADF;
		else
			error = EDEADLK;
		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)
			goto fdout;
		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);
	if (error == ERELOOKUP)
		goto restart;
fdout:
	if (fp != NULL)
		fdrop(fp, td);
	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;
	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_read_rights, &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);
		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;
		foffset = 0;
		vput(tvp);
		goto unionread;
	}
	VOP_UNLOCK(vp);
	*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 pwddesc *pdp;

	pdp = td->td_proc->p_pd;
	PWDDESC_XLOCK(pdp);
	td->td_retval[0] = pdp->pd_cmask;
	pdp->pd_cmask = uap->newmask & ALLPERMS;
	PWDDESC_XUNLOCK(pdp);
	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_NOTHING(&nd);
	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 (devfs_usecount(vp) > 0)
		VOP_REVOKE(vp, REVOKEALL);
out:
	vput(vp);
	return (error);
}

/*
 * This variant of getvnode() allows O_PATH files.  Caller should
 * ensure that returned file and vnode are only used for compatible
 * semantics.
 */
int
getvnode_path(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);
	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);
		*fpp = NULL;
		return (EINVAL);
	}

	*fpp = fp;
	return (0);
}

/*
 * 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)
{
	int error;

	error = getvnode_path(td, fd, rightsp, fpp);

	/*
	 * Filter out O_PATH file descriptors, most getvnode() callers
	 * do not call fo_ methods.
	 */
	if (error == 0 && (*fpp)->f_ops == &path_fileops) {
		fdrop(*fpp, td);
		*fpp = NULL;
		error = EBADF;
	}

	return (error);
}

/*
 * 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)
{

	return (kern_getfhat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->fname,
	    UIO_USERSPACE, uap->fhp, UIO_USERSPACE));
}

#ifndef _SYS_SYSPROTO_H_
struct getfh_args {
	char *fname;
	fhandle_t *fhp;
};
#endif
int
sys_getfh(struct thread *td, struct getfh_args *uap)
{

	return (kern_getfhat(td, 0, AT_FDCWD, uap->fname, UIO_USERSPACE,
	    uap->fhp, UIO_USERSPACE));
}

/*
 * syscall for the rpc.lockd to use to translate an open descriptor into
 * a NFS file handle.
 *
 * warning: do not remove the priv_check() call or this becomes one giant
 * security hole.
 */
#ifndef _SYS_SYSPROTO_H_
struct getfhat_args {
	int fd;
	char *path;
	fhandle_t *fhp;
	int flags;
};
#endif
int
sys_getfhat(struct thread *td, struct getfhat_args *uap)
{

	if ((uap->flags & ~(AT_SYMLINK_NOFOLLOW | AT_RESOLVE_BENEATH)) != 0)
		return (EINVAL);
	return (kern_getfhat(td, uap->flags, uap->fd, uap->path, UIO_USERSPACE,
	    uap->fhp, UIO_USERSPACE));
}

int
kern_getfhat(struct thread *td, int flags, int fd, const char *path,
    enum uio_seg pathseg, fhandle_t *fhp, enum uio_seg fhseg)
{
	struct nameidata nd;
	fhandle_t fh;
	struct vnode *vp;
	int error;

	error = priv_check(td, PRIV_VFS_GETFH);
	if (error != 0)
		return (error);
	NDINIT_AT(&nd, LOOKUP, at2cnpflags(flags, AT_SYMLINK_NOFOLLOW |
	    AT_RESOLVE_BENEATH) | LOCKLEAF | AUDITVNODE1, pathseg, path,
	    fd, td);
	error = namei(&nd);
	if (error != 0)
		return (error);
	NDFREE_NOTHING(&nd);
	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) {
		if (fhseg == UIO_USERSPACE)
			error = copyout(&fh, fhp, sizeof (fh));
		else
			memcpy(fhp, &fh, sizeof(fh));
	}
	return (error);
}

#ifndef _SYS_SYSPROTO_H_
struct fhlink_args {
	fhandle_t *fhp;
	const char *to;
};
#endif
int
sys_fhlink(struct thread *td, struct fhlink_args *uap)
{

	return (kern_fhlinkat(td, AT_FDCWD, uap->to, UIO_USERSPACE, uap->fhp));
}

#ifndef _SYS_SYSPROTO_H_
struct fhlinkat_args {
	fhandle_t *fhp;
	int tofd;
	const char *to;
};
#endif
int
sys_fhlinkat(struct thread *td, struct fhlinkat_args *uap)
{

	return (kern_fhlinkat(td, uap->tofd, uap->to, UIO_USERSPACE, uap->fhp));
}

static int
kern_fhlinkat(struct thread *td, int fd, const char *path,
    enum uio_seg pathseg, fhandle_t *fhp)
{
	fhandle_t fh;
	struct mount *mp;
	struct vnode *vp;
	int error;

	error = priv_check(td, PRIV_VFS_GETFH);
	if (error != 0)
		return (error);
	error = copyin(fhp, &fh, sizeof(fh));
	if (error != 0)
		return (error);
	do {
		bwillwrite();
		if ((mp = vfs_busyfs(&fh.fh_fsid)) == NULL)
			return (ESTALE);
		error = VFS_FHTOVP(mp, &fh.fh_fid, LK_SHARED, &vp);
		vfs_unbusy(mp);
		if (error != 0)
			return (error);
		VOP_UNLOCK(vp);
		error = kern_linkat_vp(td, vp, fd, path, pathseg);
	} while (error == EAGAIN || error == ERELOOKUP);
	return (error);
}

#ifndef _SYS_SYSPROTO_H_
struct fhreadlink_args {
	fhandle_t *fhp;
	char *buf;
	size_t bufsize;
};
#endif
int
sys_fhreadlink(struct thread *td, struct fhreadlink_args *uap)
{
	fhandle_t fh;
	struct mount *mp;
	struct vnode *vp;
	int error;

	error = priv_check(td, PRIV_VFS_GETFH);
	if (error != 0)
		return (error);
	if (uap->bufsize > IOSIZE_MAX)
		return (EINVAL);
	error = copyin(uap->fhp, &fh, sizeof(fh));
	if (error != 0)
		return (error);
	if ((mp = vfs_busyfs(&fh.fh_fsid)) == NULL)
		return (ESTALE);
	error = VFS_FHTOVP(mp, &fh.fh_fid, LK_SHARED, &vp);
	vfs_unbusy(mp);
	if (error != 0)
		return (error);
	error = kern_readlink_vp(vp, uap->buf, UIO_USERSPACE, uap->bufsize, td);
	vput(vp);
	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)
{
	return (kern_fhopen(td, uap->u_fhp, uap->flags));
}

int
kern_fhopen(struct thread *td, const struct fhandle *u_fhp, int flags)
{
	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(flags);
	/* why not allow a non-read/write open for our lockd? */
	if (((fmode & (FREAD | FWRITE)) == 0) || (fmode & O_CREAT))
		return (EINVAL);
	error = copyin(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;
	finit_vnode(fp, fmode, NULL, &vnops);
	VOP_UNLOCK(vp);
	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 = VOP_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 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
	error = VFS_STATFS(mp, buf);
out:
	vfs_unbusy(mp);
	return (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;
	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_no_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));
}

int
kern_copy_file_range(struct thread *td, int infd, off_t *inoffp, int outfd,
    off_t *outoffp, size_t len, unsigned int flags)
{
	struct file *infp, *outfp;
	struct vnode *invp, *outvp;
	int error;
	size_t retlen;
	void *rl_rcookie, *rl_wcookie;
	off_t savinoff, savoutoff;

	infp = outfp = NULL;
	rl_rcookie = rl_wcookie = NULL;
	savinoff = -1;
	error = 0;
	retlen = 0;

	if (flags != 0) {
		error = EINVAL;
		goto out;
	}
	if (len > SSIZE_MAX)
		/*
		 * Although the len argument is size_t, the return argument
		 * is ssize_t (which is signed).  Therefore a size that won't
		 * fit in ssize_t can't be returned.
		 */
		len = SSIZE_MAX;

	/* Get the file structures for the file descriptors. */
	error = fget_read(td, infd, &cap_read_rights, &infp);
	if (error != 0)
		goto out;
	if (infp->f_ops == &badfileops) {
		error = EBADF;
		goto out;
	}
	if (infp->f_vnode == NULL) {
		error = EINVAL;
		goto out;
	}
	error = fget_write(td, outfd, &cap_write_rights, &outfp);
	if (error != 0)
		goto out;
	if (outfp->f_ops == &badfileops) {
		error = EBADF;
		goto out;
	}
	if (outfp->f_vnode == NULL) {
		error = EINVAL;
		goto out;
	}

	/* Set the offset pointers to the correct place. */
	if (inoffp == NULL)
		inoffp = &infp->f_offset;
	if (outoffp == NULL)
		outoffp = &outfp->f_offset;
	savinoff = *inoffp;
	savoutoff = *outoffp;

	invp = infp->f_vnode;
	outvp = outfp->f_vnode;
	/* Sanity check the f_flag bits. */
	if ((outfp->f_flag & (FWRITE | FAPPEND)) != FWRITE ||
	    (infp->f_flag & FREAD) == 0) {
		error = EBADF;
		goto out;
	}

	/* If len == 0, just return 0. */
	if (len == 0)
		goto out;

	/*
	 * If infp and outfp refer to the same file, the byte ranges cannot
	 * overlap.
	 */
	if (invp == outvp && ((savinoff <= savoutoff && savinoff + len >
	    savoutoff) || (savinoff > savoutoff && savoutoff + len >
	    savinoff))) {
		error = EINVAL;
		goto out;
	}

	/* Range lock the byte ranges for both invp and outvp. */
	for (;;) {
		rl_wcookie = vn_rangelock_wlock(outvp, *outoffp, *outoffp +
		    len);
		rl_rcookie = vn_rangelock_tryrlock(invp, *inoffp, *inoffp +
		    len);
		if (rl_rcookie != NULL)
			break;
		vn_rangelock_unlock(outvp, rl_wcookie);
		rl_rcookie = vn_rangelock_rlock(invp, *inoffp, *inoffp + len);
		vn_rangelock_unlock(invp, rl_rcookie);
	}

	retlen = len;
	error = vn_copy_file_range(invp, inoffp, outvp, outoffp, &retlen,
	    flags, infp->f_cred, outfp->f_cred, td);
out:
	if (rl_rcookie != NULL)
		vn_rangelock_unlock(invp, rl_rcookie);
	if (rl_wcookie != NULL)
		vn_rangelock_unlock(outvp, rl_wcookie);
	if (savinoff != -1 && (error == EINTR || error == ERESTART)) {
		*inoffp = savinoff;
		*outoffp = savoutoff;
	}
	if (outfp != NULL)
		fdrop(outfp, td);
	if (infp != NULL)
		fdrop(infp, td);
	td->td_retval[0] = retlen;
	return (error);
}

int
sys_copy_file_range(struct thread *td, struct copy_file_range_args *uap)
{
	off_t inoff, outoff, *inoffp, *outoffp;
	int error;

	inoffp = outoffp = NULL;
	if (uap->inoffp != NULL) {
		error = copyin(uap->inoffp, &inoff, sizeof(off_t));
		if (error != 0)
			return (error);
		inoffp = &inoff;
	}
	if (uap->outoffp != NULL) {
		error = copyin(uap->outoffp, &outoff, sizeof(off_t));
		if (error != 0)
			return (error);
		outoffp = &outoff;
	}
	error = kern_copy_file_range(td, uap->infd, inoffp, uap->outfd,
	    outoffp, uap->len, uap->flags);
	if (error == 0 && uap->inoffp != NULL)
		error = copyout(inoffp, uap->inoffp, sizeof(off_t));
	if (error == 0 && uap->outoffp != NULL)
		error = copyout(outoffp, uap->outoffp, sizeof(off_t));
	return (error);
}