text: /*-
   * Copyright (c) 2010-2012 Semihalf.
   * 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.
   */
  
  #include <sys/cdefs.h>
  __FBSDID("$FreeBSD: soc2013/dpl/head/sys/fs/nandfs/nandfs_cleaner.c 236603 2012-05-28 16:33:58Z marcel $");
  
  #include <sys/param.h>
  #include <sys/systm.h>
  #include <sys/conf.h>
  #include <sys/kernel.h>
  #include <sys/lock.h>
  #include <sys/malloc.h>
  #include <sys/mount.h>
  #include <sys/mutex.h>
  #include <sys/buf.h>
  #include <sys/namei.h>
  #include <sys/vnode.h>
  #include <sys/bio.h>
  
  #include <fs/nandfs/nandfs_mount.h>
  #include <fs/nandfs/nandfs.h>
  #include <fs/nandfs/nandfs_subr.h>
  
  #define	NANDFS_CLEANER_KILL	1
  
  static void nandfs_cleaner(struct nandfs_device *);
  static int nandfs_cleaner_clean_segments(struct nandfs_device *,
      struct nandfs_vinfo *, uint32_t, struct nandfs_period *, uint32_t,
      struct nandfs_bdesc *, uint32_t, uint64_t *, uint32_t);
  
  static int
  nandfs_process_bdesc(struct nandfs_device *nffsdev, struct nandfs_bdesc *bd,
      uint64_t nmembs);
  
  static void
  nandfs_wakeup_wait_cleaner(struct nandfs_device *fsdev, int reason)
  {
  
  	mtx_lock(&fsdev->nd_clean_mtx);
  	if (reason == NANDFS_CLEANER_KILL)
  		fsdev->nd_cleaner_exit = 1;
  	if (fsdev->nd_cleaning == 0) {
  		fsdev->nd_cleaning = 1;
  		wakeup(&fsdev->nd_cleaning);
  	}
  	cv_wait(&fsdev->nd_clean_cv, &fsdev->nd_clean_mtx);
  	mtx_unlock(&fsdev->nd_clean_mtx);
  }
  
  int
  nandfs_start_cleaner(struct nandfs_device *fsdev)
  {
  	int error;
  
  	MPASS(fsdev->nd_cleaner == NULL);
  
  	fsdev->nd_cleaner_exit = 0;
  
  	error = kthread_add((void(*)(void *))nandfs_cleaner, fsdev, NULL,
  	    &fsdev->nd_cleaner, 0, 0, "nandfs_cleaner");
  	if (error)
  		printf("nandfs: could not start cleaner: %d\n", error);
  
  	return (error);
  }
  
  int
  nandfs_stop_cleaner(struct nandfs_device *fsdev)
  {
  
  	MPASS(fsdev->nd_cleaner != NULL);
  	nandfs_wakeup_wait_cleaner(fsdev, NANDFS_CLEANER_KILL);
  	fsdev->nd_cleaner = NULL;
  
  	DPRINTF(CLEAN, ("cleaner stopped\n"));
  	return (0);
  }
  
  static int
  nandfs_cleaner_finished(struct nandfs_device *fsdev)
  {
  	int exit;
  
  	mtx_lock(&fsdev->nd_clean_mtx);
  	fsdev->nd_cleaning = 0;
  	if (!fsdev->nd_cleaner_exit) {
  		DPRINTF(CLEAN, ("%s: sleep\n", __func__));
  		msleep(&fsdev->nd_cleaning, &fsdev->nd_clean_mtx, PRIBIO, "-",
  		    hz * nandfs_cleaner_interval);
  	}
  	exit = fsdev->nd_cleaner_exit;
  	cv_broadcast(&fsdev->nd_clean_cv);
  	mtx_unlock(&fsdev->nd_clean_mtx);
  	if (exit) {
  		DPRINTF(CLEAN, ("%s: no longer active\n", __func__));
  		return (1);
  	}
  
  	return (0);
  }
  
  static void
  print_suinfo(struct nandfs_suinfo *suinfo, int nsegs)
  {
  	int i;
  
  	for (i = 0; i < nsegs; i++) {
  		DPRINTF(CLEAN, ("%jx  %jd  %c%c%c  %10u\n",
  		    suinfo[i].nsi_num, suinfo[i].nsi_lastmod,
  		    (suinfo[i].nsi_flags &
  		    (NANDFS_SEGMENT_USAGE_ACTIVE) ? 'a' : '-'),
  		    (suinfo[i].nsi_flags &
  		    (NANDFS_SEGMENT_USAGE_DIRTY) ? 'd' : '-'),
  		    (suinfo[i].nsi_flags &
  		    (NANDFS_SEGMENT_USAGE_ERROR) ? 'e' : '-'),
  		    suinfo[i].nsi_blocks));
  	}
  }
  
  static int
  nandfs_cleaner_vblock_is_alive(struct nandfs_device *fsdev,
      struct nandfs_vinfo *vinfo, struct nandfs_cpinfo *cp, uint32_t ncps)
  {
  	int64_t idx, min, max;
  
  	if (vinfo->nvi_end >= fsdev->nd_last_cno)
  		return (1);
  
  	if (ncps == 0)
  		return (0);
  
  	if (vinfo->nvi_end < cp[0].nci_cno ||
  	    vinfo->nvi_start > cp[ncps - 1].nci_cno)
  		return (0);
  
  	idx = min = 0;
  	max = ncps - 1;
  	while (min <= max) {
  		idx = (min + max) / 2;
  		if (vinfo->nvi_start == cp[idx].nci_cno)
  			return (1);
  		if (vinfo->nvi_start < cp[idx].nci_cno)
  			max = idx - 1;
  		else
  			min = idx + 1;
  	}
  
  	return (vinfo->nvi_end >= cp[idx].nci_cno);
  }
  
  static void
  nandfs_cleaner_vinfo_mark_alive(struct nandfs_device *fsdev,
      struct nandfs_vinfo *vinfo, uint32_t nmembs, struct nandfs_cpinfo *cp,
      uint32_t ncps)
  {
  	uint32_t i;
  
  	for (i = 0; i < nmembs; i++)
  		vinfo[i].nvi_alive =
  		    nandfs_cleaner_vblock_is_alive(fsdev, &vinfo[i], cp, ncps);
  }
  
  static int
  nandfs_cleaner_bdesc_is_alive(struct nandfs_device *fsdev,
      struct nandfs_bdesc *bdesc)
  {
  	int alive;
  
  	alive = bdesc->bd_oblocknr == bdesc->bd_blocknr;
  	if (!alive)
  		MPASS(abs(bdesc->bd_oblocknr - bdesc->bd_blocknr) > 2);
  
  	return (alive);
  }
  
  static void
  nandfs_cleaner_bdesc_mark_alive(struct nandfs_device *fsdev,
      struct nandfs_bdesc *bdesc, uint32_t nmembs)
  {
  	uint32_t i;
  
  	for (i = 0; i < nmembs; i++)
  		bdesc[i].bd_alive = nandfs_cleaner_bdesc_is_alive(fsdev,
  		    &bdesc[i]);
  }
  
  static void
  nandfs_cleaner_iterate_psegment(struct nandfs_device *fsdev,
      struct nandfs_segment_summary *segsum, union nandfs_binfo *binfo,
      nandfs_daddr_t blk, struct nandfs_vinfo **vipp, struct nandfs_bdesc **bdpp)
  {
  	int i;
  
  	DPRINTF(CLEAN, ("%s nbinfos %x\n", __func__, segsum->ss_nbinfos));
  	for (i = 0; i < segsum->ss_nbinfos; i++) {
  		if (binfo[i].bi_v.bi_ino == NANDFS_DAT_INO) {
  			(*bdpp)->bd_oblocknr = blk + segsum->ss_nblocks -
  			    segsum->ss_nbinfos + i;
  			/*
  			 * XXX Hack
  			 */
  			if (segsum->ss_flags & NANDFS_SS_SR)
  				(*bdpp)->bd_oblocknr--;
  			(*bdpp)->bd_level = binfo[i].bi_dat.bi_level;
  			(*bdpp)->bd_offset = binfo[i].bi_dat.bi_blkoff;
  			(*bdpp)++;
  		} else {
  			(*vipp)->nvi_ino = binfo[i].bi_v.bi_ino;
  			(*vipp)->nvi_vblocknr = binfo[i].bi_v.bi_vblocknr;
  			(*vipp)++;
  		}
  	}
  }
  
  static int
  nandfs_cleaner_iterate_segment(struct nandfs_device *fsdev, uint64_t segno,
      struct nandfs_vinfo **vipp, struct nandfs_bdesc **bdpp, int *select)
  {
  	struct nandfs_segment_summary *segsum;
  	union nandfs_binfo *binfo;
  	struct buf *bp;
  	uint32_t nblocks;
  	nandfs_daddr_t curr, start, end;
  	int error = 0;
  
  	nandfs_get_segment_range(fsdev, segno, &start, &end);
  
  	DPRINTF(CLEAN, ("%s: segno %jx start %jx end %jx\n", __func__, segno,
  	    start, end));
  
  	*select = 0;
  
  	for (curr = start; curr < end; curr += nblocks) {
  		error = nandfs_dev_bread(fsdev, curr, NOCRED, 0, &bp);
  		if (error) {
  			brelse(bp);
  			nandfs_error("%s: couldn't load segment summary of %jx: %d\n",
  			    __func__, segno, error);
  			return (error);
  		}
  
  		segsum = (struct nandfs_segment_summary *)bp->b_data;
  		binfo = (union nandfs_binfo *)(bp->b_data + segsum->ss_bytes);
  
  		if (!nandfs_segsum_valid(segsum)) {
  			brelse(bp);
  			nandfs_error("nandfs: invalid summary of segment %jx\n", segno);
  			return (error);
  		}
  
  		DPRINTF(CLEAN, ("%s: %jx magic %x bytes %x nblocks %x nbinfos "
  		    "%x\n", __func__, segno, segsum->ss_magic, segsum->ss_bytes,
  		    segsum->ss_nblocks, segsum->ss_nbinfos));
  
  		nandfs_cleaner_iterate_psegment(fsdev, segsum, binfo, curr,
  		    vipp, bdpp);
  		nblocks = segsum->ss_nblocks;
  		brelse(bp);
  	}
  
  	if (error == 0)
  		*select = 1;
  
  	return (error);
  }
  
  static int
  nandfs_cleaner_choose_segment(struct nandfs_device *fsdev, uint64_t **segpp,
      uint64_t nsegs, uint64_t *rseg)
  {
  	struct nandfs_suinfo *suinfo;
  	uint64_t i, ssegs;
  	int error;
  
  	suinfo = malloc(sizeof(*suinfo) * nsegs, M_NANDFSTEMP,
  	    M_ZERO | M_WAITOK);
  
  	if (*rseg >= fsdev->nd_fsdata.f_nsegments)
  		*rseg = 0;
  
  retry:
  	error = nandfs_get_segment_info_filter(fsdev, suinfo, nsegs, *rseg,
  	    &ssegs, NANDFS_SEGMENT_USAGE_DIRTY,
  	    NANDFS_SEGMENT_USAGE_ACTIVE | NANDFS_SEGMENT_USAGE_ERROR |
  	    NANDFS_SEGMENT_USAGE_GC);
  	if (error) {
  		nandfs_error("%s:%d", __FILE__, __LINE__);
  		goto out;
  	}
  	if (ssegs == 0 && *rseg != 0) {
  		*rseg = 0;
  		goto retry;
  	}
  	if (ssegs > 0) {
  		print_suinfo(suinfo, ssegs);
  
  		for (i = 0; i < ssegs; i++) {
  			(**segpp) = suinfo[i].nsi_num;
  			(*segpp)++;
  		}
  		*rseg = suinfo[i - 1].nsi_num + 1;
  	}
  
  out:
  	free(suinfo, M_NANDFSTEMP);
  	return (error);
  }
  
  static int
  nandfs_cleaner_body(struct nandfs_device *fsdev, uint64_t *rseg)
  {
  	struct nandfs_vinfo *vinfo, *vip, *vipi;
  	struct nandfs_bdesc *bdesc, *bdp, *bdpi;
  	struct nandfs_cpstat cpstat;
  	struct nandfs_cpinfo *cpinfo = NULL;
  	uint64_t *segnums, *segp;
  	int select, selected;
  	int error = 0;
  	int nsegs;
  	int i;
  
  	nsegs = nandfs_cleaner_segments;
  
  	vip = vinfo = malloc(sizeof(*vinfo) *
  	    fsdev->nd_fsdata.f_blocks_per_segment * nsegs, M_NANDFSTEMP,
  	    M_ZERO | M_WAITOK);
  	bdp = bdesc = malloc(sizeof(*bdesc) *
  	    fsdev->nd_fsdata.f_blocks_per_segment * nsegs, M_NANDFSTEMP,
  	    M_ZERO | M_WAITOK);
  	segp = segnums = malloc(sizeof(*segnums) * nsegs, M_NANDFSTEMP,
  	    M_WAITOK);
  
  	error = nandfs_cleaner_choose_segment(fsdev, &segp, nsegs, rseg);
  	if (error) {
  		nandfs_error("%s:%d", __FILE__, __LINE__);
  		goto out;
  	}
  
  	if (segnums == segp)
  		goto out;
  
  	selected = 0;
  	for (i = 0; i < segp - segnums; i++) {
  		error = nandfs_cleaner_iterate_segment(fsdev, segnums[i], &vip,
  		    &bdp, &select);
  		if (error) {
  			/*
  			 * XXX deselect (see below)?
  			 */
  			goto out;
  		}
  		if (!select)
  			segnums[i] = NANDFS_NOSEGMENT;
  		else {
  			error = nandfs_markgc_segment(fsdev, segnums[i]);
  			if (error) {
  				nandfs_error("%s:%d\n", __FILE__, __LINE__);
  				goto out;
  			}
  			selected++;
  		}
  	}
  
  	if (selected == 0) {
  		MPASS(vinfo == vip);
  		MPASS(bdesc == bdp);
  		goto out;
  	}
  
  	error = nandfs_get_cpstat(fsdev->nd_cp_node, &cpstat);
  	if (error) {
  		nandfs_error("%s:%d\n", __FILE__, __LINE__);
  		goto out;
  	}
  
  	if (cpstat.ncp_nss != 0) {
  		cpinfo = malloc(sizeof(struct nandfs_cpinfo) * cpstat.ncp_nss,
  		    M_NANDFSTEMP, M_WAITOK);
  		error = nandfs_get_cpinfo(fsdev->nd_cp_node, 1, NANDFS_SNAPSHOT,
  		    cpinfo, cpstat.ncp_nss, NULL);
  		if (error) {
  			nandfs_error("%s:%d\n", __FILE__, __LINE__);
  			goto out_locked;
  		}
  	}
  
  	NANDFS_WRITELOCK(fsdev);
  	DPRINTF(CLEAN, ("%s: got lock\n", __func__));
  
  	error = nandfs_get_dat_vinfo(fsdev, vinfo, vip - vinfo);
  	if (error) {
  		nandfs_error("%s:%d\n", __FILE__, __LINE__);
  		goto out_locked;
  	}
  
  	nandfs_cleaner_vinfo_mark_alive(fsdev, vinfo, vip - vinfo, cpinfo,
  	    cpstat.ncp_nss);
  
  	error = nandfs_get_dat_bdescs(fsdev, bdesc, bdp - bdesc);
  	if (error) {
  		nandfs_error("%s:%d\n", __FILE__, __LINE__);
  		goto out_locked;
  	}
  
  	nandfs_cleaner_bdesc_mark_alive(fsdev, bdesc, bdp - bdesc);
  
  	DPRINTF(CLEAN, ("got:\n"));
  	for (vipi = vinfo; vipi < vip; vipi++) {
  		DPRINTF(CLEAN, ("v ino %jx vblocknr %jx start %jx end %jx "
  		    "alive %d\n", vipi->nvi_ino, vipi->nvi_vblocknr,
  		    vipi->nvi_start, vipi->nvi_end, vipi->nvi_alive));
  	}
  	for (bdpi = bdesc; bdpi < bdp; bdpi++) {
  		DPRINTF(CLEAN, ("b oblocknr %jx blocknr %jx offset %jx "
  		    "alive %d\n", bdpi->bd_oblocknr, bdpi->bd_blocknr,
  		    bdpi->bd_offset, bdpi->bd_alive));
  	}
  	DPRINTF(CLEAN, ("end list\n"));
  
  	error = nandfs_cleaner_clean_segments(fsdev, vinfo, vip - vinfo, NULL,
  	    0, bdesc, bdp - bdesc, segnums, segp - segnums);
  	if (error)
  		nandfs_error("%s:%d\n", __FILE__, __LINE__);
  
  out_locked:
  	NANDFS_WRITEUNLOCK(fsdev);
  out:
  	free(cpinfo, M_NANDFSTEMP);
  	free(segnums, M_NANDFSTEMP);
  	free(bdesc, M_NANDFSTEMP);
  	free(vinfo, M_NANDFSTEMP);
  
  	return (error);
  }
  
  static void
  nandfs_cleaner(struct nandfs_device *fsdev)
  {
  	uint64_t checked_seg = 0;
  	int error;
  
  	while (!nandfs_cleaner_finished(fsdev)) {
  		if (!nandfs_cleaner_enable || rebooting)
  			continue;
  
  		DPRINTF(CLEAN, ("%s: run started\n", __func__));
  
  		fsdev->nd_cleaning = 1;
  
  		error = nandfs_cleaner_body(fsdev, &checked_seg);
  
  		DPRINTF(CLEAN, ("%s: run finished error %d\n", __func__,
  		    error));
  	}
  
  	DPRINTF(CLEAN, ("%s: exiting\n", __func__));
  	kthread_exit();
  }
  
  static int
  nandfs_cleaner_clean_segments(struct nandfs_device *nffsdev,
      struct nandfs_vinfo *vinfo, uint32_t nvinfo,
      struct nandfs_period *pd, uint32_t npd,
      struct nandfs_bdesc *bdesc, uint32_t nbdesc,
      uint64_t *segments, uint32_t nsegs)
  {
  	struct nandfs_node *gc;
  	struct buf *bp;
  	uint32_t i;
  	int error = 0;
  
  	gc = nffsdev->nd_gc_node;
  
  	DPRINTF(CLEAN, ("%s: enter\n", __func__));
  
  	VOP_LOCK(NTOV(gc), LK_EXCLUSIVE);
  	for (i = 0; i < nvinfo; i++) {
  		if (!vinfo[i].nvi_alive)
  			continue;
  		DPRINTF(CLEAN, ("%s: read vblknr:%#jx blk:%#jx\n",
  		    __func__, (uintmax_t)vinfo[i].nvi_vblocknr,
  		    (uintmax_t)vinfo[i].nvi_blocknr));
  		error = nandfs_bread(nffsdev->nd_gc_node, vinfo[i].nvi_blocknr,
  		    NULL, 0, &bp);
  		if (error) {
  			nandfs_error("%s:%d", __FILE__, __LINE__);
  			VOP_UNLOCK(NTOV(gc), 0);
  			goto out;
  		}
  		nandfs_vblk_set(bp, vinfo[i].nvi_vblocknr);
  		nandfs_buf_set(bp, NANDFS_VBLK_ASSIGNED);
  		nandfs_dirty_buf(bp, 1);
  	}
  	VOP_UNLOCK(NTOV(gc), 0);
  
  	/* Delete checkpoints */
  	for (i = 0; i < npd; i++) {
  		DPRINTF(CLEAN, ("delete checkpoint: %jx\n",
  		    (uintmax_t)pd[i].p_start));
  		error = nandfs_delete_cp(nffsdev->nd_cp_node, pd[i].p_start,
  		    pd[i].p_end);
  		if (error) {
  			nandfs_error("%s:%d", __FILE__, __LINE__);
  			goto out;
  		}
  	}
  
  	/* Update vblocks */
  	for (i = 0; i < nvinfo; i++) {
  		if (vinfo[i].nvi_alive)
  			continue;
  		DPRINTF(CLEAN, ("freeing vblknr: %jx\n", vinfo[i].nvi_vblocknr));
  		error = nandfs_vblock_free(nffsdev, vinfo[i].nvi_vblocknr);
  		if (error) {
  			nandfs_error("%s:%d", __FILE__, __LINE__);
  			goto out;
  		}
  	}
  
  	error = nandfs_process_bdesc(nffsdev, bdesc, nbdesc);
  	if (error) {
  		nandfs_error("%s:%d", __FILE__, __LINE__);
  		goto out;
  	}
  
  	/* Add segments to clean */
  	if (nffsdev->nd_free_count) {
  		nffsdev->nd_free_base = realloc(nffsdev->nd_free_base,
  		    (nffsdev->nd_free_count + nsegs) * sizeof(uint64_t),
  		    M_NANDFSTEMP, M_WAITOK | M_ZERO);
  		memcpy(&nffsdev->nd_free_base[nffsdev->nd_free_count], segments,
  		    nsegs * sizeof(uint64_t));
  		nffsdev->nd_free_count += nsegs;
  	} else {
  		nffsdev->nd_free_base = malloc(nsegs * sizeof(uint64_t),
  		    M_NANDFSTEMP, M_WAITOK|M_ZERO);
  		memcpy(nffsdev->nd_free_base, segments,
  		    nsegs * sizeof(uint64_t));
  		nffsdev->nd_free_count = nsegs;
  	}
  
  out:
  
  	DPRINTF(CLEAN, ("%s: exit error %d\n", __func__, error));
  
  	return (error);
  }
  
  static int
  nandfs_process_bdesc(struct nandfs_device *nffsdev, struct nandfs_bdesc *bd,
      uint64_t nmembs)
  {
  	struct nandfs_node *dat_node;
  	struct buf *bp;
  	uint64_t i;
  	int error;
  
  	dat_node = nffsdev->nd_dat_node;
  
  	VOP_LOCK(NTOV(dat_node), LK_EXCLUSIVE);
  
  	for (i = 0; i < nmembs; i++) {
  		if (!bd[i].bd_alive)
  			continue;
  		DPRINTF(CLEAN, ("%s: idx %jx offset %jx\n",
  		    __func__, i, bd[i].bd_offset));
  		if (bd[i].bd_level) {
  			error = nandfs_bread_meta(dat_node, bd[i].bd_offset,
  			    NULL, 0, &bp);
  			if (error) {
  				nandfs_error("%s: cannot read dat node "
  				    "level:%d\n", __func__, bd[i].bd_level);
  				brelse(bp);
  				VOP_UNLOCK(NTOV(dat_node), 0);
  				return (error);
  			}
  			nandfs_dirty_buf_meta(bp, 1);
  			nandfs_bmap_dirty_blocks(VTON(bp->b_vp), bp, 1);
  		} else {
  			error = nandfs_bread(dat_node, bd[i].bd_offset, NULL,
  			    0, &bp);
  			if (error) {
  				nandfs_error("%s: cannot read dat node\n",
  				    __func__);
  				brelse(bp);
  				VOP_UNLOCK(NTOV(dat_node), 0);
  				return (error);
  			}
  			nandfs_dirty_buf(bp, 1);
  		}
  		DPRINTF(CLEAN, ("%s: bp: %p\n", __func__, bp));
  	}
  
  	VOP_UNLOCK(NTOV(dat_node), 0);
  
  	return (0);
  }
  