/*      $NetBSD: ntfs_subr.c,v 1.64 2021/05/13 08:57:29 hannken 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 1.64 2021/05/13 08:57:29 hannken 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 ||
            ntmp->ntm_sysvn[NTFS_MFTINO] == NULL) {
                struct buf *bp;
                daddr_t bn;
                off_t boff;
                size_t resid, l;
                char *data;

                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));
                boff = ntfs_btocnoff(boff);
                resid = ntfs_bntob(ntmp->ntm_bpmftrec);
                data = (char *)mfrp;
                while (resid > 0) {
                        l = MIN(resid, ntfs_cntob(1) - boff);

                        error = bread(ntmp->ntm_devvp, bn, ntfs_cntob(1),
                            0, &bp);
                        if (error) {
                                printf("%s: BREAD FAILED\n", __func__);
                                goto out;
                        }
                        memcpy(data, (char *)bp->b_data + boff, l);
                        bqrelse(bp);

                        bn += ntfs_cntobn(1);
                        boff = 0;
                        data += l;
                        resid -= l;
                }
        } 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, LK_EXCLUSIVE, &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);
}