xref: /netbsd-src/sys/fs/ntfs/ntfs_subr.c (revision a0698ed9d41653d7a2378819ad501a285ca0d401)

/*	$NetBSD: ntfs_subr.c,v 1.61 2015/03/28 19:24:05 maxv Exp $	*/

/*-
 * Copyright (c) 1998, 1999 Semen Ustimenko (semenu@FreeBSD.org)
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 *
 *	Id: ntfs_subr.c,v 1.4 1999/05/12 09:43:01 semenu Exp
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ntfs_subr.c,v 1.61 2015/03/28 19:24:05 maxv Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/buf.h>
#include <sys/file.h>
#include <sys/malloc.h>
#include <sys/lock.h>
#include <sys/kauth.h>

#include <miscfs/specfs/specdev.h>

#include <fs/ntfs/ntfs.h>
#include <fs/ntfs/ntfsmount.h>
#include <fs/ntfs/ntfs_inode.h>
#include <fs/ntfs/ntfs_vfsops.h>
#include <fs/ntfs/ntfs_subr.h>
#include <fs/ntfs/ntfs_compr.h>
#include <fs/ntfs/ntfs_ihash.h>

#ifdef NTFS_DEBUG
int ntfs_debug = NTFS_DEBUG;
#endif

MALLOC_JUSTDEFINE(M_NTFSNTVATTR, "NTFS vattr",
    "NTFS file attribute information");
MALLOC_JUSTDEFINE(M_NTFSRDATA, "NTFS res data", "NTFS resident data");
MALLOC_JUSTDEFINE(M_NTFSRUN, "NTFS vrun", "NTFS vrun storage");
MALLOC_JUSTDEFINE(M_NTFSDECOMP, "NTFS decomp", "NTFS decompression temporary");

/* Local struct used in ntfs_ntlookupfile() */
struct ntfs_lookup_ctx {
	u_int32_t	aoff;
	u_int32_t	rdsize;
	cn_t		cn;
	struct ntfs_lookup_ctx *prev;
};

static int ntfs_ntlookupattr(struct ntfsmount *, const char *, int,
	int *, char **);
static int ntfs_findvattr(struct ntfsmount *, struct ntnode *,
	struct ntvattr **, struct ntvattr **, u_int32_t, const char *,
	size_t, cn_t);
static int ntfs_uastricmp(struct ntfsmount *, const wchar *, size_t,
	const char *, size_t);
static int ntfs_uastrcmp(struct ntfsmount *, const wchar *, size_t,
	const char *, size_t);

/* table for mapping Unicode chars into uppercase; it's filled upon first
 * ntfs mount, freed upon last ntfs umount */
static wchar *ntfs_toupper_tab;
#define NTFS_U28(ch)		((((ch) & 0xE0) == 0) ? '_' : (ch) & 0xFF)
#define NTFS_TOUPPER(ch)	(ntfs_toupper_tab[(unsigned char)(ch)])
static kmutex_t ntfs_toupper_lock;
static signed int ntfs_toupper_usecount;

/* support macro for ntfs_ntvattrget() */
#define NTFS_AALPCMP(aalp,type,name,namelen) (				\
  (aalp->al_type == type) && (aalp->al_namelen == namelen) &&		\
  !ntfs_uastrcmp(ntmp, aalp->al_name,aalp->al_namelen,name,namelen) )

int
ntfs_ntvattrrele(struct ntvattr *vap)
{
	dprintf(("%s: ino: %llu, type: 0x%x\n", __func__,
	    (unsigned long long)vap->va_ip->i_number, vap->va_type));
	ntfs_ntrele(vap->va_ip);
	return (0);
}

/*
 * find the attribute in the ntnode
 */
static int
ntfs_findvattr(struct ntfsmount *ntmp, struct ntnode *ip, struct ntvattr **lvapp,
    struct ntvattr **vapp, u_int32_t type, const char *name, size_t namelen,
    cn_t vcn)
{
	int error;
	struct ntvattr *vap;

	if ((ip->i_flag & IN_LOADED) == 0) {
		dprintf(("%s: node not loaded, ino: %llu\n", __func__,
		    (unsigned long long)ip->i_number));
		error = ntfs_loadntnode(ntmp,ip);
		if (error) {
			printf("%s: FAILED TO LOAD INO: %llu\n", __func__,
			    (unsigned long long)ip->i_number);
			return (error);
		}
	}

	*lvapp = NULL;
	*vapp = NULL;
	for (vap = ip->i_valist.lh_first; vap; vap = vap->va_list.le_next) {
		ddprintf(("%s: type: 0x%x, vcn: %qu - %qu\n", __func__,
		    vap->va_type, (long long) vap->va_vcnstart,
		    (long long) vap->va_vcnend));
		if ((vap->va_type == type) &&
		    (vap->va_vcnstart <= vcn) && (vap->va_vcnend >= vcn) &&
		    (vap->va_namelen == namelen) &&
		    (strncmp(name, vap->va_name, namelen) == 0)) {
			*vapp = vap;
			ntfs_ntref(vap->va_ip);
			return (0);
		}
		if (vap->va_type == NTFS_A_ATTRLIST)
			*lvapp = vap;
	}

	return (-1);
}

/*
 * Search attribute specified in ntnode (load ntnode if necessary).
 * If not found but ATTR_A_ATTRLIST present, read it in and search through.
 *
 * ntnode should be locked
 */
int
ntfs_ntvattrget(struct ntfsmount *ntmp, struct ntnode *ip, u_int32_t type,
    const char *name, cn_t vcn, struct ntvattr **vapp)
{
	struct ntvattr *lvap = NULL;
	struct attr_attrlist *aalp;
	struct attr_attrlist *nextaalp;
	struct ntnode *newip;
	void *alpool;
	size_t namelen, len;
	int error;

	*vapp = NULL;

	if (name) {
		dprintf(("%s: ino: %llu, type: 0x%x, name: %s, vcn: %qu\n",
		    __func__, (unsigned long long)ip->i_number, type, name,
		    (long long)vcn));
		namelen = strlen(name);
	} else {
		dprintf(("%s: ino: %llu, type: 0x%x, vcn: %qu\n", __func__,
		    (unsigned long long)ip->i_number, type, (long long)vcn));
		name = "";
		namelen = 0;
	}

	error = ntfs_findvattr(ntmp, ip, &lvap, vapp, type, name, namelen, vcn);
	if (error >= 0)
		return (error);

	if (!lvap) {
		dprintf(("%s: NON-EXISTENT ATTRIBUTE: "
		    "ino: %llu, type: 0x%x, name: %s, vcn: %qu\n", __func__,
		    (unsigned long long)ip->i_number, type, name,
		    (long long)vcn));
		return (ENOENT);
	}
	/* Scan $ATTRIBUTE_LIST for requested attribute */
	len = lvap->va_datalen;
	alpool = malloc(len, M_TEMP, M_WAITOK);
	error = ntfs_readntvattr_plain(ntmp, ip, lvap, 0, len, alpool, &len,
			NULL);
	if (error)
		goto out;

	aalp = (struct attr_attrlist *) alpool;
	nextaalp = NULL;

	for (; len > 0; aalp = nextaalp) {
		KASSERT(aalp != NULL);
		dprintf(("%s: attrlist: ino: %d, attr: 0x%x, vcn: %qu\n",
		    __func__, aalp->al_inumber, aalp->al_type,
		    (long long) aalp->al_vcnstart));

		if (len > aalp->reclen) {
			nextaalp = NTFS_NEXTREC(aalp, struct attr_attrlist *);
		} else {
			nextaalp = NULL;
		}
		len -= aalp->reclen;

		if (!NTFS_AALPCMP(aalp, type, name, namelen) ||
		    (nextaalp && (nextaalp->al_vcnstart <= vcn) &&
		     NTFS_AALPCMP(nextaalp, type, name, namelen)))
			continue;

		dprintf(("%s: attribute in ino: %d\n", __func__,
				 aalp->al_inumber));

		error = ntfs_ntlookup(ntmp, aalp->al_inumber, &newip);
		if (error) {
			printf("%s: can't lookup ino %d"
			    " for %" PRId64 " attr %x: error %d\n", __func__,
			    aalp->al_inumber, ip->i_number, type, error);
			goto out;
		}
		/* XXX have to lock ntnode */
		error = ntfs_findvattr(ntmp, newip, &lvap, vapp,
				type, name, namelen, vcn);
		ntfs_ntput(newip);
		if (error == 0)
			goto out;
		printf("%s: ATTRLIST ERROR.\n", __func__);
		break;
	}
	error = ENOENT;

	dprintf(("%s: NON-EXISTENT ATTRIBUTE: ino: %llu, type: 0x%x, "
	    "name: %.*s, vcn: %qu\n", __func__,
	    (unsigned long long)ip->i_number, type, (int)namelen,
	    name, (long long)vcn));
out:
	free(alpool, M_TEMP);
	return (error);
}

/*
 * Read ntnode from disk, make ntvattr list.
 *
 * ntnode should be locked
 */
int
ntfs_loadntnode(struct ntfsmount *ntmp, struct ntnode *ip)
{
	struct filerec *mfrp;
	int error, off;
	struct attr *ap;
	struct ntvattr *nvap;

	dprintf(("%s: loading ino: %llu\n", __func__,
	    (unsigned long long)ip->i_number));

	mfrp = malloc(ntfs_bntob(ntmp->ntm_bpmftrec), M_TEMP, M_WAITOK);

	if (ip->i_number < NTFS_SYSNODESNUM) {
		struct buf *bp;
		daddr_t bn;
		off_t boff;

		dprintf(("%s: read system node\n", __func__));

		/*
		 * Make sure we always read full cluster to
		 * prevent buffer cache inconsistency.
		 */
		boff = ntfs_cntob(ntmp->ntm_mftcn) +
		    ntfs_bntob(ntmp->ntm_bpmftrec) * ip->i_number;
		bn = ntfs_cntobn(ntfs_btocn(boff));
		off = ntfs_btocnoff(boff);

		error = bread(ntmp->ntm_devvp, bn, ntfs_cntob(1),
		    0, &bp);
		if (error) {
			printf("%s: BREAD FAILED\n", __func__);
			goto out;
		}
		memcpy(mfrp, (char *)bp->b_data + off,
		    ntfs_bntob(ntmp->ntm_bpmftrec));
		bqrelse(bp);
	} else {
		struct vnode   *vp;

		vp = ntmp->ntm_sysvn[NTFS_MFTINO];
		error = ntfs_readattr(ntmp, VTONT(vp), NTFS_A_DATA, NULL,
		    ip->i_number * ntfs_bntob(ntmp->ntm_bpmftrec),
		    ntfs_bntob(ntmp->ntm_bpmftrec), mfrp, NULL);
		if (error) {
			printf("%s: ntfs_readattr failed\n", __func__);
			goto out;
		}
	}

	/* Check if magic and fixups are correct */
	error = ntfs_procfixups(ntmp, NTFS_FILEMAGIC, (void *)mfrp,
				ntfs_bntob(ntmp->ntm_bpmftrec));
	if (error) {
		printf("%s: BAD MFT RECORD %d\n", __func__,
		    (u_int32_t) ip->i_number);
		goto out;
	}

	dprintf(("%s: load attrs for ino: %llu\n", __func__,
	    (unsigned long long)ip->i_number));
	off = mfrp->fr_attroff;
	ap = (struct attr *) ((char *)mfrp + off);

	LIST_INIT(&ip->i_valist);

	while (ap->a_hdr.a_type != -1) {
		error = ntfs_attrtontvattr(ntmp, &nvap, ap);
		if (error)
			break;
		nvap->va_ip = ip;

		LIST_INSERT_HEAD(&ip->i_valist, nvap, va_list);

		off += ap->a_hdr.reclen;
		ap = (struct attr *) ((char *)mfrp + off);
	}
	if (error) {
		printf("%s: failed to load attr ino: %llu\n", __func__,
		    (unsigned long long)ip->i_number);
		goto out;
	}

	ip->i_mainrec = mfrp->fr_mainrec;
	ip->i_nlink = mfrp->fr_nlink;
	ip->i_frflag = mfrp->fr_flags;

	ip->i_flag |= IN_LOADED;

out:
	free(mfrp, M_TEMP);
	return (error);
}

/*
 * Routine locks ntnode and increase usecount, just opposite of
 * ntfs_ntput().
 */
int
ntfs_ntget(struct ntnode *ip)
{
	dprintf(("%s: get ntnode %llu: %p, usecount: %d\n", __func__,
	    (unsigned long long)ip->i_number, ip, ip->i_usecount));

	mutex_enter(&ip->i_interlock);
	ip->i_usecount++;
	while (ip->i_busy != 0) {
		cv_wait(&ip->i_lock, &ip->i_interlock);
	}
	ip->i_busy = 1;
	mutex_exit(&ip->i_interlock);

	return 0;
}

/*
 * Routine search ntnode in hash, if found: lock, inc usecount and return.
 * If not in hash allocate structure for ntnode, prefill it, lock,
 * inc count and return.
 *
 * ntnode returned locked
 */
int
ntfs_ntlookup(struct ntfsmount *ntmp, ino_t ino, struct ntnode **ipp)
{
	struct ntnode *ip;

	dprintf(("%s: looking for ntnode %llu\n", __func__,
	    (unsigned long long)ino));

	if ((*ipp = ntfs_nthashlookup(ntmp->ntm_dev, ino)) != NULL) {
		ntfs_ntget(*ipp);
		dprintf(("%s: ntnode %llu: %p, usecount: %d\n", __func__,
		    (unsigned long long)ino, *ipp, (*ipp)->i_usecount));
		return (0);
	}

	ip = malloc(sizeof(*ip), M_NTFSNTNODE, M_WAITOK|M_ZERO);
	ddprintf(("%s: allocating ntnode: %llu: %p\n", __func__,
	    (unsigned long long)ino, ip));

	mutex_enter(&ntfs_hashlock);
	if ((*ipp = ntfs_nthashlookup(ntmp->ntm_dev, ino)) != NULL) {
		mutex_exit(&ntfs_hashlock);
		ntfs_ntget(*ipp);
		free(ip, M_NTFSNTNODE);
		dprintf(("%s: ntnode %llu: %p, usecount: %d\n", __func__,
		    (unsigned long long)ino, *ipp, (*ipp)->i_usecount));
		return (0);
	}

	/* Generic initialization */
	ip->i_devvp = ntmp->ntm_devvp;
	ip->i_dev = ntmp->ntm_dev;
	ip->i_number = ino;
	ip->i_mp = ntmp;

	/* init lock and lock the newborn ntnode */
	cv_init(&ip->i_lock, "ntfslk");
	mutex_init(&ip->i_interlock, MUTEX_DEFAULT, IPL_NONE);
	ntfs_ntget(ip);

	ntfs_nthashins(ip);

	mutex_exit(&ntfs_hashlock);

	*ipp = ip;

	dprintf(("%s: ntnode %llu: %p, usecount: %d\n", __func__,
	    (unsigned long long)ino, ip, ip->i_usecount));

	return (0);
}

/*
 * Decrement usecount of ntnode and unlock it, if usecount reaches zero,
 * deallocate ntnode.
 *
 * ntnode should be locked on entry, and unlocked on return.
 */
void
ntfs_ntput(struct ntnode *ip)
{
	struct ntvattr *vap;

	dprintf(("%s: rele ntnode %llu: %p, usecount: %d\n", __func__,
	    (unsigned long long)ip->i_number, ip, ip->i_usecount));

	mutex_enter(&ip->i_interlock);
	ip->i_usecount--;

#ifdef DIAGNOSTIC
	if (ip->i_usecount < 0) {
		panic("ntfs_ntput: ino: %llu usecount: %d ",
		    (unsigned long long)ip->i_number, ip->i_usecount);
	}
#endif

	ip->i_busy = 0;
	cv_signal(&ip->i_lock);
	mutex_exit(&ip->i_interlock);

	if (ip->i_usecount == 0) {
		dprintf(("%s: deallocating ntnode: %llu\n", __func__,
		    (unsigned long long)ip->i_number));

		ntfs_nthashrem(ip);

		while (ip->i_valist.lh_first != NULL) {
			vap = ip->i_valist.lh_first;
			LIST_REMOVE(vap,va_list);
			ntfs_freentvattr(vap);
		}
		mutex_destroy(&ip->i_interlock);
		cv_destroy(&ip->i_lock);
		free(ip, M_NTFSNTNODE);
	}
}

/*
 * increment usecount of ntnode
 */
void
ntfs_ntref(struct ntnode *ip)
{
	mutex_enter(&ip->i_interlock);
	ip->i_usecount++;
	mutex_exit(&ip->i_interlock);

	dprintf(("%s: ino %llu, usecount: %d\n", __func__,
	    (unsigned long long)ip->i_number, ip->i_usecount));
}

/*
 * Decrement usecount of ntnode.
 */
void
ntfs_ntrele(struct ntnode *ip)
{
	dprintf(("%s: rele ntnode %llu: %p, usecount: %d\n", __func__,
	    (unsigned long long)ip->i_number, ip, ip->i_usecount));

	mutex_enter(&ip->i_interlock);
	ip->i_usecount--;

	if (ip->i_usecount < 0)
		panic("%s: ino: %llu usecount: %d ", __func__,
		    (unsigned long long)ip->i_number, ip->i_usecount);
	mutex_exit(&ip->i_interlock);
}

/*
 * Deallocate all memory allocated for ntvattr
 */
void
ntfs_freentvattr(struct ntvattr *vap)
{
	if (vap->va_flag & NTFS_AF_INRUN) {
		if (vap->va_vruncn)
			free(vap->va_vruncn, M_NTFSRUN);
		if (vap->va_vruncl)
			free(vap->va_vruncl, M_NTFSRUN);
	} else {
		if (vap->va_datap)
			free(vap->va_datap, M_NTFSRDATA);
	}
	free(vap, M_NTFSNTVATTR);
}

/*
 * Convert disk image of attribute into ntvattr structure,
 * runs are expanded also.
 */
int
ntfs_attrtontvattr(struct ntfsmount *ntmp, struct ntvattr **rvapp,
   struct attr *rap)
{
	int error, i;
	struct ntvattr *vap;

	error = 0;
	*rvapp = NULL;

	vap = malloc(sizeof(*vap), M_NTFSNTVATTR, M_WAITOK|M_ZERO);
	vap->va_ip = NULL;
	vap->va_flag = rap->a_hdr.a_flag;
	vap->va_type = rap->a_hdr.a_type;
	vap->va_compression = rap->a_hdr.a_compression;
	vap->va_index = rap->a_hdr.a_index;

	ddprintf(("%s: type: 0x%x, index: %d", __func__,
	    vap->va_type, vap->va_index));

	vap->va_namelen = rap->a_hdr.a_namelen;
	if (rap->a_hdr.a_namelen) {
		wchar *unp = (wchar *)((char *)rap + rap->a_hdr.a_nameoff);
		ddprintf((", name:["));
		for (i = 0; i < vap->va_namelen; i++) {
			vap->va_name[i] = unp[i];
			ddprintf(("%c", vap->va_name[i]));
		}
		ddprintf(("]"));
	}
	if (vap->va_flag & NTFS_AF_INRUN) {
		ddprintf((", nonres."));
		vap->va_datalen = rap->a_nr.a_datalen;
		vap->va_allocated = rap->a_nr.a_allocated;
		vap->va_vcnstart = rap->a_nr.a_vcnstart;
		vap->va_vcnend = rap->a_nr.a_vcnend;
		vap->va_compressalg = rap->a_nr.a_compressalg;
		error = ntfs_runtovrun(&(vap->va_vruncn), &(vap->va_vruncl),
		    &(vap->va_vruncnt),
		    (u_int8_t *) rap + rap->a_nr.a_dataoff);
	} else {
		vap->va_compressalg = 0;
		ddprintf((", res."));
		vap->va_datalen = rap->a_r.a_datalen;
		vap->va_allocated = rap->a_r.a_datalen;
		vap->va_vcnstart = 0;
		vap->va_vcnend = ntfs_btocn(vap->va_allocated);
		vap->va_datap = malloc(vap->va_datalen, M_NTFSRDATA, M_WAITOK);
		memcpy(vap->va_datap, (char *)rap + rap->a_r.a_dataoff,
		    rap->a_r.a_datalen);
	}
	ddprintf((", len: %qu", (long long)vap->va_datalen));

	if (error)
		free(vap, M_NTFSNTVATTR);
	else
		*rvapp = vap;

	ddprintf(("\n"));

	return (error);
}

/*
 * Expand run into more utilizable and more memory eating format.
 */
int
ntfs_runtovrun(cn_t **rcnp, cn_t **rclp, u_long *rcntp, u_int8_t *run)
{
	u_int32_t off, sz, i;
	cn_t *cn, *cl;
	u_long cnt;
	cn_t prev, tmp;

	off = 0;
	cnt = 0;
	i = 0;
	while (run[off]) {
		off += (run[off] & 0xF) + ((run[off] >> 4) & 0xF) + 1;
		cnt++;
	}
	cn = malloc(cnt * sizeof(*cn), M_NTFSRUN, M_WAITOK);
	cl = malloc(cnt * sizeof(*cl), M_NTFSRUN, M_WAITOK);

	off = 0;
	cnt = 0;
	prev = 0;
	while (run[off]) {
		sz = run[off++];
		cl[cnt] = 0;

		for (i = 0; i < (sz & 0xF); i++)
			cl[cnt] += (u_int32_t) run[off++] << (i << 3);

		sz >>= 4;
		if (run[off + sz - 1] & 0x80) {
			tmp = ((u_int64_t) - 1) << (sz << 3);
			for (i = 0; i < sz; i++)
				tmp |= (u_int64_t) run[off++] << (i << 3);
		} else {
			tmp = 0;
			for (i = 0; i < sz; i++)
				tmp |= (u_int64_t) run[off++] << (i << 3);
		}
		if (tmp)
			prev = cn[cnt] = prev + tmp;
		else
			cn[cnt] = tmp;

		cnt++;
	}
	*rcnp = cn;
	*rclp = cl;
	*rcntp = cnt;
	return (0);
}

/*
 * Compare unicode and ascii string case insens.
 */
static int
ntfs_uastricmp(struct ntfsmount *ntmp, const wchar *ustr, size_t ustrlen,
    const char *astr, size_t astrlen)
{
	size_t i;
	int res;

	for (i = 0; i < ustrlen && astrlen > 0; i++) {
		res = (*ntmp->ntm_wcmp)(NTFS_TOUPPER(ustr[i]),
		    NTFS_TOUPPER((*ntmp->ntm_wget)(&astr, &astrlen)) );
		if (res)
			return res;
	}

	if (i == ustrlen && astrlen == 0)
		return 0;
	else if (i == ustrlen)
		return -1;
	else
		return 1;
}

/*
 * Compare unicode and ascii string case sens.
 */
static int
ntfs_uastrcmp(struct ntfsmount *ntmp, const wchar *ustr, size_t ustrlen,
    const char *astr, size_t astrlen)
{
	size_t i;
	int res;

	for (i = 0; (i < ustrlen) && astrlen > 0; i++) {
		res = (*ntmp->ntm_wcmp)(ustr[i],
		    (*ntmp->ntm_wget)(&astr, &astrlen));
		if (res)
			return res;
	}

	if (i == ustrlen && astrlen == 0)
		return 0;
	else if (i == ustrlen)
		return -1;
	else
		return 1;
}

/*
 * Lookup attribute name in format: [[:$ATTR_TYPE]:$ATTR_NAME],
 * $ATTR_TYPE is searched in attrdefs read from $AttrDefs.
 * If $ATTR_TYPE not specified, ATTR_A_DATA assumed.
 */
static int
ntfs_ntlookupattr(struct ntfsmount *ntmp, const char *name, int namelen,
    int *attrtype, char **attrname)
{
	const char *sys;
	size_t syslen, i;
	struct ntvattrdef *adp;

	if (namelen == 0)
		return (0);

	if (name[0] == '$') {
		sys = name;
		for (syslen = 0; syslen < namelen; syslen++) {
			if (sys[syslen] == ':') {
				name++;
				namelen--;
				break;
			}
		}
		name += syslen;
		namelen -= syslen;

		adp = ntmp->ntm_ad;
		for (i = 0; i < ntmp->ntm_adnum; i++, adp++){
			if (syslen != adp->ad_namelen ||
			    strncmp(sys, adp->ad_name, syslen) != 0)
				continue;

			*attrtype = adp->ad_type;
			goto out;
		}
		return (ENOENT);
	} else
		*attrtype = NTFS_A_DATA;

out:
	if (namelen) {
		*attrname = malloc(namelen+1, M_TEMP, M_WAITOK);
		memcpy((*attrname), name, namelen);
		(*attrname)[namelen] = '\0';
	}

	return (0);
}

/*
 * Lookup specified node for filename, matching cnp,
 * return referenced vnode with fnode filled.
 */
int
ntfs_ntlookupfile(struct ntfsmount *ntmp, struct vnode *vp,
    struct componentname *cnp, struct vnode **vpp)
{
	struct fnode   *fp = VTOF(vp);
	struct ntnode  *ip = FTONT(fp);
	struct ntvattr *vap = NULL;	/* Root attribute */
	cn_t            cn = 0;	/* VCN in current attribute */
	void *        rdbuf = NULL;	/* Buffer to read directory's blocks  */
	u_int32_t       blsize;
	u_int32_t       rdsize;	/* Length of data to read from current block */
	struct attr_indexentry *iep;
	int             error, res, anamelen, fnamelen;
	const char     *fname,*aname;
	u_int32_t       aoff;
	int attrtype = NTFS_A_DATA;
	char *attrname = NULL;
	struct vnode   *nvp;
	int fullscan = 0;
	struct ntfs_lookup_ctx *lookup_ctx = NULL, *tctx;

	error = ntfs_ntget(ip);
	if (error)
		return (error);

	error = ntfs_ntvattrget(ntmp, ip, NTFS_A_INDXROOT, "$I30", 0, &vap);
	if (error || (vap->va_flag & NTFS_AF_INRUN)) {
		error = ENOTDIR;
		goto fail;
	}

	/*
	 * Divide file name into: foofilefoofilefoofile[:attrspec]
	 * Store like this:       fname:fnamelen       [aname:anamelen]
	 */
	fname = cnp->cn_nameptr;
	aname = NULL;
	anamelen = 0;
	for (fnamelen = 0; fnamelen < cnp->cn_namelen; fnamelen++)
		if (fname[fnamelen] == ':') {
			aname = fname + fnamelen + 1;
			anamelen = cnp->cn_namelen - fnamelen - 1;
			dprintf(("%s: %s (%d), attr: %s (%d)\n", __func__,
				fname, fnamelen, aname, anamelen));
			break;
		}

	blsize = vap->va_a_iroot->ir_size;
	dprintf(("%s: blksz: %d\n", __func__, blsize));
	rdbuf = malloc(blsize, M_TEMP, M_WAITOK);

loop:
	rdsize = vap->va_datalen;
	dprintf(("%s: rdsz: %d\n", __func__, rdsize));

	error = ntfs_readattr(ntmp, ip, NTFS_A_INDXROOT, "$I30",
	    0, rdsize, rdbuf, NULL);
	if (error)
		goto fail;

	aoff = sizeof(struct attr_indexroot);

	do {
		iep = (struct attr_indexentry *) ((char *)rdbuf + aoff);

		for (; !(iep->ie_flag & NTFS_IEFLAG_LAST) && (rdsize > aoff);
			aoff += iep->reclen,
			iep = (struct attr_indexentry *) ((char *)rdbuf + aoff))
		{
			ddprintf(("%s: fscan: %d, %d\n", __func__,
				  (u_int32_t) iep->ie_number,
				  (u_int32_t) iep->ie_fnametype));

			/* check the name - the case-insensitive check
			 * has to come first, to break from this for loop
			 * if needed, so we can dive correctly */
			res = ntfs_uastricmp(ntmp, iep->ie_fname,
				iep->ie_fnamelen, fname, fnamelen);
			if (!fullscan) {
				if (res > 0)
					break;
				if (res < 0)
					continue;
			}

			if (iep->ie_fnametype == 0 ||
			    !(ntmp->ntm_flag & NTFS_MFLAG_CASEINS))
			{
				res = ntfs_uastrcmp(ntmp, iep->ie_fname,
					iep->ie_fnamelen, fname, fnamelen);
				if (res != 0 && !fullscan)
					continue;
			}

			/* if we perform full scan, the file does not match
			 * and this is subnode, dive */
			if (fullscan && res != 0) {
				if (iep->ie_flag & NTFS_IEFLAG_SUBNODE) {
					tctx = malloc(sizeof(*tctx), M_TEMP,
					    M_WAITOK);
					tctx->aoff	= aoff + iep->reclen;
					tctx->rdsize	= rdsize;
					tctx->cn	= cn;
					tctx->prev	= lookup_ctx;
					lookup_ctx = tctx;
					break;
				} else
					continue;
			}

			if (aname) {
				error = ntfs_ntlookupattr(ntmp, aname, anamelen,
				    &attrtype, &attrname);
				if (error)
					goto fail;
			}

			/* Check if we've found ourselves */
			if ((iep->ie_number == ip->i_number) &&
			    (attrtype == fp->f_attrtype) &&
			    !strcmp(attrname ? attrname : "", fp->f_attrname))
			{
				vref(vp);
				*vpp = vp;
				error = 0;
				goto fail;
			}

			/* vget node */
			error = ntfs_vgetex(ntmp->ntm_mountp, iep->ie_number,
			    attrtype, attrname ? attrname : "", 0, &nvp);

			/* free the buffer returned by ntfs_ntlookupattr() */
			if (attrname) {
				free(attrname, M_TEMP);
				attrname = NULL;
			}

			if (error)
				goto fail;

			*vpp = nvp;
			goto fail;
		}

		/* Dive if possible */
		if (iep->ie_flag & NTFS_IEFLAG_SUBNODE) {
			dprintf(("%s: diving\n", __func__));

			cn = *(cn_t *) ((char *)rdbuf + aoff +
					iep->reclen - sizeof(cn_t));
			rdsize = blsize;

			error = ntfs_readattr(ntmp, ip, NTFS_A_INDX, "$I30",
			    ntfs_cntob(cn), rdsize, rdbuf, NULL);
			if (error)
				goto fail;

			error = ntfs_procfixups(ntmp, NTFS_INDXMAGIC,
			    rdbuf, rdsize);
			if (error)
				goto fail;

			aoff = (((struct attr_indexalloc *) rdbuf)->ia_hdrsize +
				0x18);
		} else if (fullscan && lookup_ctx) {
			cn = lookup_ctx->cn;
			aoff = lookup_ctx->aoff;
			rdsize = lookup_ctx->rdsize;

			error = ntfs_readattr(ntmp, ip,
				(cn == 0) ? NTFS_A_INDXROOT : NTFS_A_INDX,
				"$I30", ntfs_cntob(cn), rdsize, rdbuf, NULL);
			if (error)
				goto fail;

			if (cn != 0) {
				error = ntfs_procfixups(ntmp, NTFS_INDXMAGIC,
				    rdbuf, rdsize);
				if (error)
					goto fail;
			}

			tctx = lookup_ctx;
			lookup_ctx = lookup_ctx->prev;
			free(tctx, M_TEMP);
		} else {
			dprintf(("%s: nowhere to dive :-(\n", __func__));
			error = ENOENT;
			break;
		}
	} while (1);

	/* perform full scan if no entry was found */
	if (!fullscan && error == ENOENT) {
		fullscan = 1;
		cn = 0;		/* need zero, used by lookup_ctx */

		ddprintf(("%s: fullscan performed for: %.*s\n", __func__,
		    (int) fnamelen, fname));
		goto loop;
	}

	dprintf(("finish\n"));

fail:
	if (attrname)
		free(attrname, M_TEMP);
	if (lookup_ctx) {
		while(lookup_ctx) {
			tctx = lookup_ctx;
			lookup_ctx = lookup_ctx->prev;
			free(tctx, M_TEMP);
		}
	}
	if (vap)
		ntfs_ntvattrrele(vap);
	if (rdbuf)
		free(rdbuf, M_TEMP);
	ntfs_ntput(ip);
	return (error);
}

/*
 * Check if name type is permitted to show.
 */
int
ntfs_isnamepermitted(struct ntfsmount *ntmp, struct attr_indexentry *iep)
{
	if (ntmp->ntm_flag & NTFS_MFLAG_ALLNAMES)
		return 1;

	switch (iep->ie_fnametype) {
	case 2:
		ddprintf(("%s: skipped DOS name\n", __func__));
		return 0;
	case 0: case 1: case 3:
		return 1;
	default:
		printf("%s: WARNING! Unknown file name type: %d\n", __func__,
		    iep->ie_fnametype);
		break;
	}
	return 0;
}

/*
 * Read ntfs dir like stream of attr_indexentry, not like btree of them.
 * This is done by scanning $BITMAP:$I30 for busy clusters and reading them.
 * Of course $INDEX_ROOT:$I30 is read before. Last read values are stored in
 * fnode, so we can skip toward record number num almost immediately.
 * Anyway this is rather slow routine. The problem is that we don't know
 * how many records are there in $INDEX_ALLOCATION:$I30 block.
 */
int
ntfs_ntreaddir(struct ntfsmount *ntmp, struct fnode *fp, u_int32_t num,
    struct attr_indexentry **riepp)
{
	struct ntnode  *ip = FTONT(fp);
	struct ntvattr *vap = NULL;	/* IndexRoot attribute */
	struct ntvattr *bmvap = NULL;	/* BitMap attribute */
	struct ntvattr *iavap = NULL;	/* IndexAllocation attribute */
	void *        rdbuf;		/* Buffer to read directory's blocks  */
	u_char         *bmp = NULL;	/* Bitmap */
	u_int32_t       blsize;		/* Index allocation size (2048) */
	u_int32_t       rdsize;		/* Length of data to read */
	u_int32_t       attrnum;	/* Current attribute type */
	u_int32_t       cpbl = 1;	/* Clusters per directory block */
	u_int32_t       blnum;
	struct attr_indexentry *iep;
	int             error = ENOENT;
	u_int32_t       aoff, cnum;

	dprintf(("%s: read ino: %llu, num: %d\n", __func__,
	    (unsigned long long)ip->i_number, num));
	error = ntfs_ntget(ip);
	if (error)
		return (error);

	error = ntfs_ntvattrget(ntmp, ip, NTFS_A_INDXROOT, "$I30", 0, &vap);
	if (error) {
		error = ENOTDIR;
		goto fail;
	}

	if (fp->f_dirblbuf == NULL) {
		fp->f_dirblsz = vap->va_a_iroot->ir_size;
		fp->f_dirblbuf = malloc(MAX(vap->va_datalen, fp->f_dirblsz),
		    M_NTFSDIR, M_WAITOK);
	}

	blsize = fp->f_dirblsz;
	rdbuf = fp->f_dirblbuf;

	dprintf(("%s: rdbuf: %p, blsize: %d\n", __func__, rdbuf, blsize));

	if (vap->va_a_iroot->ir_flag & NTFS_IRFLAG_INDXALLOC) {
		error = ntfs_ntvattrget(ntmp, ip, NTFS_A_INDXBITMAP, "$I30",
					0, &bmvap);
		if (error) {
			error = ENOTDIR;
			goto fail;
		}
		bmp = (u_char *) malloc(bmvap->va_datalen, M_TEMP, M_WAITOK);
		error = ntfs_readattr(ntmp, ip, NTFS_A_INDXBITMAP, "$I30", 0,
		    bmvap->va_datalen, bmp, NULL);
		if (error)
			goto fail;

		error = ntfs_ntvattrget(ntmp, ip, NTFS_A_INDX, "$I30",
					0, &iavap);
		if (error) {
			error = ENOTDIR;
			goto fail;
		}
		cpbl = ntfs_btocn(blsize + ntfs_cntob(1) - 1);
		dprintf(("%s: indexalloc: %qu, cpbl: %d\n", __func__,
		    (long long)iavap->va_datalen, cpbl));
	} else {
		dprintf(("%s: w/o BitMap and IndexAllocation\n", __func__));
		iavap = bmvap = NULL;
		bmp = NULL;
	}

	/* Try use previous values */
	if ((fp->f_lastdnum < num) && (fp->f_lastdnum != 0)) {
		attrnum = fp->f_lastdattr;
		aoff = fp->f_lastdoff;
		blnum = fp->f_lastdblnum;
		cnum = fp->f_lastdnum;
	} else {
		attrnum = NTFS_A_INDXROOT;
		aoff = sizeof(struct attr_indexroot);
		blnum = 0;
		cnum = 0;
	}

	do {
		dprintf(("%s: scan: 0x%x, %d, %d, %d, %d\n", __func__,
			 attrnum, (u_int32_t) blnum, cnum, num, aoff));
		rdsize = (attrnum == NTFS_A_INDXROOT) ? vap->va_datalen : blsize;
		error = ntfs_readattr(ntmp, ip, attrnum, "$I30",
				ntfs_cntob(blnum * cpbl), rdsize, rdbuf, NULL);
		if (error)
			goto fail;

		if (attrnum == NTFS_A_INDX) {
			error = ntfs_procfixups(ntmp, NTFS_INDXMAGIC,
						rdbuf, rdsize);
			if (error)
				goto fail;
		}
		if (aoff == 0)
			aoff = (attrnum == NTFS_A_INDX) ?
				(0x18 + ((struct attr_indexalloc *) rdbuf)->ia_hdrsize) :
				sizeof(struct attr_indexroot);

		iep = (struct attr_indexentry *) ((char *)rdbuf + aoff);
		for (; !(iep->ie_flag & NTFS_IEFLAG_LAST) && (rdsize > aoff);
			aoff += iep->reclen,
			iep = (struct attr_indexentry *) ((char *)rdbuf + aoff))
		{
			if (!ntfs_isnamepermitted(ntmp, iep))
				continue;
			if (cnum >= num) {
				fp->f_lastdnum = cnum;
				fp->f_lastdoff = aoff;
				fp->f_lastdblnum = blnum;
				fp->f_lastdattr = attrnum;

				*riepp = iep;

				error = 0;
				goto fail;
			}
			cnum++;
		}

		if (iavap) {
			if (attrnum == NTFS_A_INDXROOT)
				blnum = 0;
			else
				blnum++;

			while (ntfs_cntob(blnum * cpbl) < iavap->va_datalen) {
				if (bmp[blnum >> 3] & (1 << (blnum & 3)))
					break;
				blnum++;
			}

			attrnum = NTFS_A_INDX;
			aoff = 0;
			if (ntfs_cntob(blnum * cpbl) >= iavap->va_datalen)
				break;
			dprintf(("%s: blnum: %d\n", __func__,
			    (u_int32_t) blnum));
		}
	} while (iavap);

	*riepp = NULL;
	fp->f_lastdnum = 0;

fail:
	if (vap)
		ntfs_ntvattrrele(vap);
	if (bmvap)
		ntfs_ntvattrrele(bmvap);
	if (iavap)
		ntfs_ntvattrrele(iavap);
	if (bmp)
		free(bmp, M_TEMP);
	ntfs_ntput(ip);
	return (error);
}

/*
 * Convert NTFS times that are in 100 ns units and begins from
 * 1601 Jan 1 into unix times.
 */
struct timespec
ntfs_nttimetounix(u_int64_t nt)
{
	struct timespec t;

	/* WindowNT times are in 100 ns and from 1601 Jan 1 */
	t.tv_nsec = (nt % (1000 * 1000 * 10)) * 100;
	t.tv_sec = nt / (1000 * 1000 * 10) -
		369LL * 365LL * 24LL * 60LL * 60LL -
		89LL * 1LL * 24LL * 60LL * 60LL;
	return (t);
}

/*
 * This is one of the write routines.
 */
int
ntfs_writeattr_plain(struct ntfsmount *ntmp, struct ntnode *ip,
    u_int32_t attrnum, char *attrname, off_t roff, size_t rsize, void *rdata,
    size_t *initp, struct uio *uio)
{
	size_t init;
	int error = 0;
	off_t off = roff, left = rsize, towrite;
	void *data = rdata;
	struct ntvattr *vap;
	*initp = 0;

	while (left) {
		error = ntfs_ntvattrget(ntmp, ip, attrnum, attrname,
					ntfs_btocn(off), &vap);
		if (error)
			return (error);
		towrite = MIN(left, ntfs_cntob(vap->va_vcnend + 1) - off);
		ddprintf(("%s: o: %qd, s: %qd (%qu - %qu)\n", __func__,
		    (long long) off, (long long) towrite,
		    (long long) vap->va_vcnstart,
		    (long long) vap->va_vcnend));
		error = ntfs_writentvattr_plain(ntmp, ip, vap,
		    off - ntfs_cntob(vap->va_vcnstart),
		    towrite, data, &init, uio);
		if (error) {
			dprintf(("%s: "
			    "ntfs_writentvattr_plain failed: o: %qd, s: %qd\n",
			    __func__, (long long) off, (long long) towrite));
			dprintf(("%s: attrib: %qu - %qu\n", __func__,
			    (long long) vap->va_vcnstart,
			    (long long) vap->va_vcnend));
			ntfs_ntvattrrele(vap);
			break;
		}
		ntfs_ntvattrrele(vap);
		left -= towrite;
		off += towrite;
		data = (char *)data + towrite;
		*initp += init;
	}

	return (error);
}

/*
 * This is one of the write routines.
 *
 * ntnode should be locked.
 */
int
ntfs_writentvattr_plain(struct ntfsmount *ntmp, struct ntnode *ip,
    struct ntvattr *vap, off_t roff, size_t rsize, void *rdata, size_t *initp,
    struct uio *uio)
{
	int error = 0;
	off_t off;
	int cnt;
	cn_t ccn, ccl, cn, left, cl;
	void *data = rdata;
	daddr_t lbn;
	struct buf *bp;
	size_t tocopy;

	*initp = 0;

	if ((vap->va_flag & NTFS_AF_INRUN) == 0) {
		dprintf(("%s: CAN'T WRITE RES. ATTRIBUTE\n", __func__));
		return ENOTTY;
	}

	ddprintf(("%s: data in run: %lu chains\n", __func__,
		 vap->va_vruncnt));

	off = roff;
	left = rsize;
	ccl = 0;
	ccn = 0;
	cnt = 0;
	for (; left && (cnt < vap->va_vruncnt); cnt++) {
		ccn = vap->va_vruncn[cnt];
		ccl = vap->va_vruncl[cnt];

		ddprintf(("%s: left %qu, cn: 0x%qx, cl: %qu, off: %qd\n",
		    __func__, (long long) left, (long long) ccn,
		    (long long) ccl, (long long) off));

		if (ntfs_cntob(ccl) < off) {
			off -= ntfs_cntob(ccl);
			cnt++;
			continue;
		}
		if (!ccn && ip->i_number != NTFS_BOOTINO)
			continue; /* XXX */

		ccl -= ntfs_btocn(off);
		cn = ccn + ntfs_btocn(off);
		off = ntfs_btocnoff(off);

		while (left && ccl) {
			/*
			 * Always read and write single clusters at a time -
			 * we need to avoid requesting differently-sized
			 * blocks at the same disk offsets to avoid
			 * confusing the buffer cache.
			 */
			tocopy = MIN(left, ntfs_cntob(1) - off);
			cl = ntfs_btocl(tocopy + off);
			KASSERT(cl == 1 && tocopy <= ntfs_cntob(1));
			ddprintf(("%s: write: cn: 0x%qx cl: %qu, off: %qd "
			    "len: %qu, left: %qu\n", __func__,
			    (long long) cn, (long long) cl,
			    (long long) off, (long long) tocopy,
			    (long long) left));
			if ((off == 0) && (tocopy == ntfs_cntob(cl))) {
				lbn = ntfs_cntobn(cn);
				bp = getblk(ntmp->ntm_devvp, lbn,
					    ntfs_cntob(cl), 0, 0);
				clrbuf(bp);
			} else {
				error = bread(ntmp->ntm_devvp, ntfs_cntobn(cn),
				    ntfs_cntob(cl), B_MODIFY, &bp);
				if (error)
					return (error);
			}
			if (uio)
				uiomove((char *)bp->b_data + off, tocopy, uio);
			else
				memcpy((char *)bp->b_data + off, data, tocopy);
			bawrite(bp);
			data = (char *)data + tocopy;
			*initp += tocopy;
			off = 0;
			left -= tocopy;
			cn += cl;
			ccl -= cl;
		}
	}

	if (left) {
		printf("%s: POSSIBLE RUN ERROR\n", __func__);
		error = EINVAL;
	}

	return (error);
}

/*
 * This is one of the read routines.
 *
 * ntnode should be locked.
 */
int
ntfs_readntvattr_plain(struct ntfsmount *ntmp, struct ntnode *ip,
    struct ntvattr *vap, off_t roff, size_t rsize, void *rdata, size_t *initp,
    struct uio *uio)
{
	int error = 0;
	off_t off;

	*initp = 0;
	if (vap->va_flag & NTFS_AF_INRUN) {
		int cnt;
		cn_t ccn, ccl, cn, left, cl;
		void *data = rdata;
		struct buf *bp;
		size_t tocopy;

		ddprintf(("%s: data in run: %lu chains\n", __func__,
			 vap->va_vruncnt));

		off = roff;
		left = rsize;
		ccl = 0;
		ccn = 0;
		cnt = 0;
		while (left && (cnt < vap->va_vruncnt)) {
			ccn = vap->va_vruncn[cnt];
			ccl = vap->va_vruncl[cnt];

			ddprintf(("%s: left %qu, cn: 0x%qx, cl: %qu, "
			    "off: %qd\n", __func__,
			    (long long) left, (long long) ccn,
			    (long long) ccl, (long long) off));

			if (ntfs_cntob(ccl) < off) {
				off -= ntfs_cntob(ccl);
				cnt++;
				continue;
			}
			if (ccn || ip->i_number == NTFS_BOOTINO) {
				ccl -= ntfs_btocn(off);
				cn = ccn + ntfs_btocn(off);
				off = ntfs_btocnoff(off);

				while (left && ccl) {
					/*
					 * Always read single clusters at a
					 * time - we need to avoid reading
					 * differently-sized blocks at the
					 * same disk offsets to avoid
					 * confusing the buffer cache.
					 */
					tocopy = MIN(left,
					    ntfs_cntob(1) - off);
					cl = ntfs_btocl(tocopy + off);
					KASSERT(cl == 1 &&
					    tocopy <= ntfs_cntob(1));

					ddprintf(("%s: read: cn: 0x%qx cl: %qu,"
					    " off: %qd len: %qu, left: %qu\n",
					    __func__, (long long) cn,
					    (long long) cl,
					    (long long) off,
					    (long long) tocopy,
					    (long long) left));
					error = bread(ntmp->ntm_devvp,
						      ntfs_cntobn(cn),
						      ntfs_cntob(cl),
						      0, &bp);
					if (error) {
						return (error);
					}
					if (uio) {
						uiomove((char *)bp->b_data + off,
							tocopy, uio);
					} else {
						memcpy(data, (char *)bp->b_data + off,
							tocopy);
					}
					brelse(bp, 0);
					data = (char *)data + tocopy;
					*initp += tocopy;
					off = 0;
					left -= tocopy;
					cn += cl;
					ccl -= cl;
				}
			} else {
				tocopy = MIN(left, ntfs_cntob(ccl) - off);
				ddprintf(("%s: hole: ccn: 0x%qx ccl: %qu, "
				    "off: %qd, len: %qu, left: %qu\n", __func__,
				    (long long) ccn, (long long) ccl,
				    (long long) off, (long long) tocopy,
				    (long long) left));
				left -= tocopy;
				off = 0;
				if (uio) {
					char vbuf[] = "";
					size_t remains = tocopy;
					for (; remains; remains--)
						uiomove(vbuf, 1, uio);
				} else
					memset(data, 0, tocopy);
				data = (char *)data + tocopy;
			}
			cnt++;
		}
		if (left) {
			printf("%s: POSSIBLE RUN ERROR\n", __func__);
			error = E2BIG;
		}
	} else {
		ddprintf(("%s: data is in mft record\n", __func__));
		if (uio)
			uiomove((char *)vap->va_datap + roff, rsize, uio);
		else
			memcpy(rdata, (char *)vap->va_datap + roff, rsize);
		*initp += rsize;
	}

	return (error);
}

/*
 * This is one of the read routines.
 */
int
ntfs_readattr_plain(struct ntfsmount *ntmp, struct ntnode *ip,
    u_int32_t attrnum, const char *attrname, off_t roff, size_t rsize,
    void *rdata, size_t *initp, struct uio *uio)
{
	size_t init;
	int error = 0;
	off_t off = roff, left = rsize, toread;
	void *data = rdata;
	struct ntvattr *vap;
	*initp = 0;

	while (left) {
		error = ntfs_ntvattrget(ntmp, ip, attrnum, attrname,
		    ntfs_btocn(off), &vap);
		if (error)
			return (error);
		toread = MIN(left, ntfs_cntob(vap->va_vcnend + 1) - off);
		ddprintf(("%s: o: %qd, s: %qd (%qu - %qu)\n", __func__,
		    (long long) off, (long long) toread,
		    (long long) vap->va_vcnstart,
		    (long long) vap->va_vcnend));
		error = ntfs_readntvattr_plain(ntmp, ip, vap,
		    off - ntfs_cntob(vap->va_vcnstart),
		    toread, data, &init, uio);
		if (error) {
			printf("%s: ntfs_readntvattr_plain failed: o: %qd, "
			    "s: %qd\n", __func__,
			    (long long) off, (long long) toread);
			printf("%s: attrib: %qu - %qu\n", __func__,
			    (long long) vap->va_vcnstart,
			    (long long) vap->va_vcnend);
			ntfs_ntvattrrele(vap);
			break;
		}
		ntfs_ntvattrrele(vap);
		left -= toread;
		off += toread;
		data = (char *)data + toread;
		*initp += init;
	}

	return (error);
}

/*
 * This is one of the read routines.
 */
int
ntfs_readattr(struct ntfsmount *ntmp, struct ntnode *ip, u_int32_t attrnum,
    const char *attrname, off_t roff, size_t rsize, void *rdata,
    struct uio *uio)
{
	int error = 0;
	struct ntvattr *vap;
	size_t init;

	ddprintf(("%s: reading %llu: 0x%x, from %qd size %qu bytes\n",
	    __func__, (unsigned long long)ip->i_number, attrnum,
	    (long long)roff, (long long)rsize));

	error = ntfs_ntvattrget(ntmp, ip, attrnum, attrname, 0, &vap);
	if (error)
		return (error);

	if ((roff > vap->va_datalen) ||
	    (roff + rsize > vap->va_datalen)) {
		printf("%s: offset too big: %qd (%qd) > %qu\n", __func__,
		    (long long) roff, (long long) (roff + rsize),
		    (long long) vap->va_datalen);
		ntfs_ntvattrrele(vap);
		return (E2BIG);
	}
	if (vap->va_compression && vap->va_compressalg) {
		u_int8_t *cup, *uup;
		off_t off, left, tocopy;
		void *data;
		cn_t cn;

		left = rsize;
		data = rdata;
		ddprintf(("%s: compression: %d\n", __func__,
		    vap->va_compressalg));

		cup = malloc(ntfs_cntob(NTFS_COMPUNIT_CL),
		    M_NTFSDECOMP, M_WAITOK);
		uup = malloc(ntfs_cntob(NTFS_COMPUNIT_CL),
		    M_NTFSDECOMP, M_WAITOK);

		cn = (ntfs_btocn(roff)) & (~(NTFS_COMPUNIT_CL - 1));
		off = roff - ntfs_cntob(cn);

		while (left) {
			error = ntfs_readattr_plain(ntmp, ip, attrnum,
			    attrname, ntfs_cntob(cn),
			    ntfs_cntob(NTFS_COMPUNIT_CL), cup, &init, NULL);
			if (error)
				break;

			tocopy = MIN(left, ntfs_cntob(NTFS_COMPUNIT_CL) - off);

			if (init == ntfs_cntob(NTFS_COMPUNIT_CL)) {
				if (uio)
					uiomove(cup + off, tocopy, uio);
				else
					memcpy(data, cup + off, tocopy);
			} else if (init == 0) {
				if (uio) {
					char vbuf[] = "";
					size_t remains = tocopy;
					for (; remains; remains--)
						uiomove(vbuf, 1, uio);
				}
				else
					memset(data, 0, tocopy);
			} else {
				error = ntfs_uncompunit(ntmp, uup, cup);
				if (error)
					break;
				if (uio)
					uiomove(uup + off, tocopy, uio);
				else
					memcpy(data, uup + off, tocopy);
			}

			left -= tocopy;
			data = (char *)data + tocopy;
			off += tocopy - ntfs_cntob(NTFS_COMPUNIT_CL);
			cn += NTFS_COMPUNIT_CL;
		}

		free(uup, M_NTFSDECOMP);
		free(cup, M_NTFSDECOMP);
	} else
		error = ntfs_readattr_plain(ntmp, ip, attrnum, attrname,
		    roff, rsize, rdata, &init, uio);
	ntfs_ntvattrrele(vap);
	return (error);
}

#if UNUSED_CODE
int
ntfs_parserun(cn_t *cn, cn_t *cl, u_int8_t *run, u_long len, u_long *off)
{
	u_int8_t sz;
	int i;

	if (NULL == run) {
		printf("%s: run == NULL\n", __func__);
		return (EINVAL);
	}
	sz = run[(*off)++];
	if (0 == sz) {
		printf("%s: trying to go out of run\n", __func__);
		return (E2BIG);
	}
	*cl = 0;
	if ((sz & 0xF) > 8 || (*off) + (sz & 0xF) > len) {
		printf("%s: bad run: length too big: sz: 0x%02x "
		    "(%ld < %ld + sz)\n", __func__, sz, len, *off);
		return (EINVAL);
	}
	for (i = 0; i < (sz & 0xF); i++)
		*cl += (u_int32_t) run[(*off)++] << (i << 3);

	sz >>= 4;
	if ((sz & 0xF) > 8 || (*off) + (sz & 0xF) > len) {
		printf("%s: bad run: length too big: sz: 0x%02x "
		    "(%ld < %ld + sz)\n", __func__, sz, len, *off);
		return (EINVAL);
	}
	for (i = 0; i < (sz & 0xF); i++)
		*cn += (u_int32_t) run[(*off)++] << (i << 3);

	return (0);
}
#endif

/*
 * Process fixup routine on given buffer.
 */
int
ntfs_procfixups(struct ntfsmount *ntmp, u_int32_t magic, void *xbufv,
    size_t len)
{
	char *xbuf = xbufv;
	struct fixuphdr *fhp = (struct fixuphdr *) xbuf;
	int i;
	u_int16_t fixup;
	u_int16_t *fxp, *cfxp;

	if (fhp->fh_magic == 0)
		return (EINVAL);
	if (fhp->fh_magic != magic) {
		printf("%s: magic doesn't match: %08x != %08x\n", __func__,
		    fhp->fh_magic, magic);
		return (EINVAL);
	}
	if ((fhp->fh_fnum - 1) * ntmp->ntm_bps != len) {
		printf("%s: bad fixups number: %d for %ld bytes block\n",
		    __func__, fhp->fh_fnum, (long)len);	/* XXX printf kludge */
		return (EINVAL);
	}
	if (fhp->fh_foff >= ntmp->ntm_spc * ntmp->ntm_mftrecsz * ntmp->ntm_bps) {
		printf("%s: invalid offset: %x", __func__, fhp->fh_foff);
		return (EINVAL);
	}
	fxp = (u_int16_t *) (xbuf + fhp->fh_foff);
	cfxp = (u_int16_t *) (xbuf + ntmp->ntm_bps - 2);
	fixup = *fxp++;
	for (i = 1; i < fhp->fh_fnum; i++, fxp++) {
		if (*cfxp != fixup) {
			printf("%s: fixup %d doesn't match\n", __func__, i);
			return (EINVAL);
		}
		*cfxp = *fxp;
		cfxp = (u_int16_t *)((char *)cfxp + ntmp->ntm_bps);
	}
	return (0);
}

#if UNUSED_CODE
int
ntfs_runtocn(cn_t *cn, struct ntfsmount *ntmp, u_int8_t *run, u_long len,
    cn_t vcn)
{
	cn_t ccn = 0, ccl = 0;
	u_long off = 0;
	int error = 0;

#ifdef NTFS_DEBUG
	int i;
	printf("%s: run: %p, %ld bytes, vcn:%ld\n", __func__,
	    run, len, (u_long) vcn);
	printf("%s: run: ", __func__);
	for (i = 0; i < len; i++)
		printf("0x%02x ", run[i]);
	printf("\n");
#endif

	if (NULL == run) {
		printf("%s: run == NULL\n", __func__);
		return (EINVAL);
	}
	do {
		if (run[off] == 0) {
			printf("%s: vcn too big\n", __func__);
			return (E2BIG);
		}
		vcn -= ccl;
		error = ntfs_parserun(&ccn, &ccl, run, len, &off);
		if (error) {
			printf("%s: ntfs_parserun failed\n", __func__);
			return (error);
		}
	} while (ccl <= vcn);
	*cn = ccn + vcn;
	return (0);
}
#endif

/*
 * this initializes toupper table & dependent variables to be ready for
 * later work
 */
void
ntfs_toupper_init(void)
{
	ntfs_toupper_tab = NULL;
	mutex_init(&ntfs_toupper_lock, MUTEX_DEFAULT, IPL_NONE);
	ntfs_toupper_usecount = 0;
}

/*
 * if the ntfs_toupper_tab[] is filled already, just raise use count;
 * otherwise read the data from the filesystem we are currently mounting
 */
int
ntfs_toupper_use(struct mount *mp, struct ntfsmount *ntmp)
{
	int error = 0;
	struct vnode *vp;

	/* get exclusive access */
	mutex_enter(&ntfs_toupper_lock);

	/* only read the translation data from a file if it hasn't been
	 * read already */
	if (ntfs_toupper_tab)
		goto out;

	/*
	 * Read in Unicode lowercase -> uppercase translation file.
	 * XXX for now, just the first 256 entries are used anyway,
	 * so don't bother reading more
	 */
	ntfs_toupper_tab = malloc(256 * 256 * sizeof(*ntfs_toupper_tab),
	    M_NTFSRDATA, M_WAITOK);

	if ((error = VFS_VGET(mp, NTFS_UPCASEINO, &vp)))
		goto out;
	error = ntfs_readattr(ntmp, VTONT(vp), NTFS_A_DATA, NULL,
	    0, 256 * 256 * sizeof(*ntfs_toupper_tab), (char *)ntfs_toupper_tab,
	    NULL);
	vput(vp);

out:
	ntfs_toupper_usecount++;
	mutex_exit(&ntfs_toupper_lock);
	return (error);
}

/*
 * lower the use count and if it reaches zero, free the memory
 * tied by toupper table
 */
void
ntfs_toupper_unuse(void)
{
	/* get exclusive access */
	mutex_enter(&ntfs_toupper_lock);

	ntfs_toupper_usecount--;
	if (ntfs_toupper_usecount == 0) {
		free(ntfs_toupper_tab, M_NTFSRDATA);
		ntfs_toupper_tab = NULL;
	}
#ifdef DIAGNOSTIC
	else if (ntfs_toupper_usecount < 0) {
		panic("ntfs_toupper_unuse(): use count negative: %d",
			ntfs_toupper_usecount);
	}
#endif

	/* release the lock */
	mutex_exit(&ntfs_toupper_lock);
}