parted-1.8.7/libparted/fs/fat/clstdup.c - nest-learning-thermostat/5.1.5/parted - Git at Google

 /*
     libparted
     Copyright (C) 1998, 1999, 2000, 2001, 2007 Free Software Foundation, Inc.

     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 2 of the License, or
     (at your option) any later version.

     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.

     You should have received a copy of the GNU General Public License
     along with this program; if not, write to the Free Software
     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */

 #include <config.h>
 #include <string.h>

 #include "fat.h"

 #ifndef DISCOVER_ONLY

 static int
 needs_duplicating (const FatOpContext* ctx, FatFragment frag)
 {
 	FatSpecific*	old_fs_info = FAT_SPECIFIC (ctx->old_fs);
 	FatCluster	cluster = fat_frag_to_cluster (ctx->old_fs, frag);
 	FatClusterFlag	flag;

 	PED_ASSERT (cluster >= 2 && cluster < old_fs_info->cluster_count + 2,
 		    return 0);

 	flag = fat_get_fragment_flag (ctx->old_fs, frag);
 	switch (flag) {
 	case FAT_FLAG_FREE:
 		return 0;

 	case FAT_FLAG_DIRECTORY:
 		return 1;

 	case FAT_FLAG_FILE:
 		return fat_op_context_map_static_fragment (ctx, frag) == -1;

 	case FAT_FLAG_BAD:
 		return 0;
 	}

 	return 0;
 }

 static int
 search_next_fragment (FatOpContext* ctx)
 {
 	FatSpecific*	fs_info = FAT_SPECIFIC (ctx->old_fs);

 	for (; ctx->buffer_offset < fs_info->frag_count; ctx->buffer_offset++) {
 		if (needs_duplicating (ctx, ctx->buffer_offset))
 			return 1;
 	}
 	return 0;	/* all done! */
 }

 static int
 read_marked_fragments (FatOpContext* ctx, FatFragment length)
 {
 	FatSpecific*		fs_info = FAT_SPECIFIC (ctx->old_fs);
 	int			status;
 	FatFragment		i;

 	ped_exception_fetch_all ();
 	status = fat_read_fragments (ctx->old_fs, fs_info->buffer,
 				     ctx->buffer_offset, length);
 	ped_exception_leave_all ();
 	if (status)
 		return 1;

 	ped_exception_catch ();

 /* something bad happened, so read fragments one by one.  (The error may
    have occurred on an unused fragment: who cares) */
 	for (i = 0; i < length; i++) {
 		if (ctx->buffer_map [i]) {
 			if (!fat_read_fragment (ctx->old_fs,
 			      fs_info->buffer + i * fs_info->frag_size,
 			      ctx->buffer_offset + i))
 				return 0;
 		}
 	}

 	return 1;
 }

 static int
 fetch_fragments (FatOpContext* ctx)
 {
 	FatSpecific*	old_fs_info = FAT_SPECIFIC (ctx->old_fs);
 	FatFragment	fetch_length = 0;
 	FatFragment	frag;

 	for (frag = 0; frag < ctx->buffer_frags; frag++)
 		ctx->buffer_map [frag] = -1;

 	for (frag = 0;
 	     frag < ctx->buffer_frags
 		&& ctx->buffer_offset + frag < old_fs_info->frag_count;
 	     frag++) {
 		if (needs_duplicating (ctx, ctx->buffer_offset + frag)) {
 			ctx->buffer_map [frag] = 1;
 			fetch_length = frag + 1;
 		}
 	}

 	if (!read_marked_fragments (ctx, fetch_length))
 		return 0;

 	return 1;
 }

 /*****************************************************************************
  * here starts the write code.  All assumes that ctx->buffer_map [first] and
  * ctx->buffer_map [last] are occupied by fragments that need to be duplicated.
  *****************************************************************************/

 /* finds the first fragment that is not going to get overwritten (that needs to
    get read in) */
 static FatFragment
 get_first_underlay (const FatOpContext* ctx, int first, int last)
 {
 	int		old;
 	FatFragment	new;

 	PED_ASSERT (first <= last, return 0);

 	new = ctx->buffer_map [first];
 	for (old = first + 1; old <= last; old++) {
 		if (ctx->buffer_map [old] == -1)
 			continue;
 		new++;
 		if (ctx->buffer_map [old] != new)
 			return new;
 	}
 	return -1;
 }

 /* finds the last fragment that is not going to get overwritten (that needs to
    get read in) */
 static FatFragment
 get_last_underlay (const FatOpContext* ctx, int first, int last)
 {
 	int		old;
 	FatFragment	new;

 	PED_ASSERT (first <= last, return 0);

 	new = ctx->buffer_map [last];
 	for (old = last - 1; old >= first; old--) {
 		if (ctx->buffer_map [old] == -1)
 			continue;
 		new--;
 		if (ctx->buffer_map [old] != new)
 			return new;
 	}
 	return -1;
 }

 /* "underlay" refers to the "static" fragments, that remain unchanged.
  * when writing large chunks at a time, we don't want to clobber these,
  * so we read them in, and write them back again.  MUCH quicker that way.
  */
 static int
 quick_group_write_read_underlay (FatOpContext* ctx, int first, int last)
 {
 	FatSpecific*	new_fs_info = FAT_SPECIFIC (ctx->new_fs);
 	FatFragment	first_underlay;
 	FatFragment	last_underlay;
 	FatFragment	underlay_length;

 	PED_ASSERT (first <= last, return 0);

 	first_underlay = get_first_underlay (ctx, first, last);
 	if (first_underlay == -1)
 		return 1;
 	last_underlay = get_last_underlay (ctx, first, last);

 	PED_ASSERT (first_underlay <= last_underlay, return 0);

 	underlay_length = last_underlay - first_underlay + 1;
 	if (!fat_read_fragments (ctx->new_fs,
 				new_fs_info->buffer
 				   + (first_underlay - ctx->buffer_map [first])
 					* new_fs_info->frag_size,
 				first_underlay,
 				underlay_length))
 		return 0;
 	return 1;
 }

 /* quick_group_write() makes no attempt to recover from errors - just
  * does things fast.  If there is an error, slow_group_write() is
  * called.
  *    Note: we do syncing writes, to make sure there isn't any
  * error writing out.  It's rather difficult recovering from errors
  * further on.
  */
 static int
 quick_group_write (FatOpContext* ctx, int first, int last)
 {
 	FatSpecific*		old_fs_info = FAT_SPECIFIC (ctx->old_fs);
 	FatSpecific*		new_fs_info = FAT_SPECIFIC (ctx->new_fs);
 	int			active_length;
 	int			i;
 	int			offset;

 	PED_ASSERT (first <= last, return 0);

 	ped_exception_fetch_all ();
 	if (!quick_group_write_read_underlay (ctx, first, last))
 		goto error;

 	for (i = first; i <= last; i++) {
 		if (ctx->buffer_map [i] == -1)
 			continue;

 		offset = ctx->buffer_map [i] - ctx->buffer_map [first];
 		memcpy (new_fs_info->buffer + offset * new_fs_info->frag_size,
 			old_fs_info->buffer + i * new_fs_info->frag_size,
 			new_fs_info->frag_size);
 	}

 	active_length = ctx->buffer_map [last] - ctx->buffer_map [first] + 1;
 	if (!fat_write_sync_fragments (ctx->new_fs, new_fs_info->buffer,
 				       ctx->buffer_map [first], active_length))
 		goto error;

 	ped_exception_leave_all ();
 	return 1;

 error:
 	ped_exception_catch ();
 	ped_exception_leave_all ();
 	return 0;
 }

 /* Writes fragments out, one at a time, avoiding errors on redundant writes
  * on damaged parts of the disk we already know about.  If there's an error
  * on one of the required fragments, it gets marked as bad, and a replacement
  * is found.
  */
 static int
 slow_group_write (FatOpContext* ctx, int first, int last)
 {
 	FatSpecific*		old_fs_info = FAT_SPECIFIC (ctx->old_fs);
 	FatSpecific*		new_fs_info = FAT_SPECIFIC (ctx->new_fs);
 	int			i;

 	PED_ASSERT (first <= last, return 0);

 	for (i = first; i <= last; i++) {
 		if (ctx->buffer_map [i] == -1)
 			continue;

 		while (!fat_write_sync_fragment (ctx->new_fs,
 			      old_fs_info->buffer + i * old_fs_info->frag_size,
 			      ctx->buffer_map [i])) {
 			fat_table_set_bad (new_fs_info->fat,
 					   ctx->buffer_map [i]);
 			ctx->buffer_map [i] = fat_table_alloc_cluster
 						(new_fs_info->fat);
 			if (ctx->buffer_map [i] == 0)
 				return 0;
 		}
 	}
 	return 1;
 }

 static int
 update_remap (FatOpContext* ctx, int first, int last)
 {
 	int		i;

 	PED_ASSERT (first <= last, return 0);

 	for (i = first; i <= last; i++) {
 		if (ctx->buffer_map [i] == -1)
 			continue;
 		ctx->remap [ctx->buffer_offset + i] = ctx->buffer_map [i];
 	}

 	return 1;
 }

 static int
 group_write (FatOpContext* ctx, int first, int last)
 {
 	PED_ASSERT (first <= last, return 0);

 	if (!quick_group_write (ctx, first, last)) {
 		if (!slow_group_write (ctx, first, last))
 			return 0;
 	}
 	if (!update_remap (ctx, first, last))
 		return 0;
 	return 1;
 }

 /* assumes fragment size and new_fs's cluster size are equal */
 static int
 write_fragments (FatOpContext* ctx)
 {
 	FatSpecific*		old_fs_info = FAT_SPECIFIC (ctx->old_fs);
 	FatSpecific*		new_fs_info = FAT_SPECIFIC (ctx->new_fs);
 	int			group_start;
 	int			group_end = -1;	/* shut gcc up! */
 	FatFragment		mapped_length;
 	FatFragment		i;
 	FatCluster		new_cluster;

 	PED_ASSERT (ctx->buffer_offset < old_fs_info->frag_count, return 0);

 	group_start = -1;
 	for (i = 0; i < ctx->buffer_frags; i++) {
 		if (ctx->buffer_map [i] == -1)
 			continue;

 		ctx->frags_duped++;

 		new_cluster = fat_table_alloc_cluster (new_fs_info->fat);
 		if (!new_cluster)
 			return 0;
 		fat_table_set_eof (new_fs_info->fat, new_cluster);
 		ctx->buffer_map [i] = fat_cluster_to_frag (ctx->new_fs,
 							   new_cluster);

 		if (group_start == -1)
 			group_start = group_end = i;

 		PED_ASSERT (ctx->buffer_map [i]
 				>= ctx->buffer_map [group_start],
 			    return 0);

 		mapped_length = ctx->buffer_map [i]
 				- ctx->buffer_map [group_start] + 1;
 		if (mapped_length <= ctx->buffer_frags) {
 			group_end = i;
 		} else {
 			/* ran out of room in the buffer, so write this group,
 			 * and start a new one...
 			 */
 			if (!group_write (ctx, group_start, group_end))
 				return 0;
 			group_start = group_end = i;
 		}
 	}

 	PED_ASSERT (group_start != -1, return 0);

 	if (!group_write (ctx, group_start, group_end))
 		return 0;
 	return 1;
 }

 /*  default all fragments to unmoved
  */
 static void
 init_remap (FatOpContext* ctx)
 {
 	FatSpecific*		old_fs_info = FAT_SPECIFIC (ctx->old_fs);
 	FatFragment		i;

 	for (i = 0; i < old_fs_info->frag_count; i++)
 		ctx->remap[i] = fat_op_context_map_static_fragment (ctx, i);
 }

 static FatFragment
 count_frags_to_dup (FatOpContext* ctx)
 {
 	FatSpecific*	fs_info = FAT_SPECIFIC (ctx->old_fs);
 	FatFragment	i;
 	FatFragment	total;

 	total = 0;

 	for (i = 0; i < fs_info->frag_count; i++) {
 		if (needs_duplicating (ctx, i))
 			total++;
 	}

 	return total;
 }

 /*  duplicates unreachable file clusters, and all directory clusters
  */
 int
 fat_duplicate_clusters (FatOpContext* ctx, PedTimer* timer)
 {
 	FatFragment	total_frags_to_dup;

 	init_remap (ctx);
 	total_frags_to_dup = count_frags_to_dup (ctx);

 	ped_timer_reset (timer);
 	ped_timer_set_state_name (timer, "moving data");

 	ctx->buffer_offset = 0;
 	ctx->frags_duped = 0;
 	while (search_next_fragment (ctx)) {
 		ped_timer_update (
 			timer, 1.0 * ctx->frags_duped / total_frags_to_dup);

 		if (!fetch_fragments (ctx))
 			return 0;
 		if (!write_fragments (ctx))
 			return 0;
 		ctx->buffer_offset += ctx->buffer_frags;
 	}

 	ped_timer_update (timer, 1.0);
 	return 1;
 }

 #endif /* !DISCOVER_ONLY */
	/*
	libparted
	Copyright (C) 1998, 1999, 2000, 2001, 2007 Free Software Foundation, Inc.

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to the Free Software
	Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
	*/

	#include <config.h>
	#include <string.h>

	#include "fat.h"

	#ifndef DISCOVER_ONLY

	static int
	needs_duplicating (const FatOpContext* ctx, FatFragment frag)
	{
	FatSpecific* old_fs_info = FAT_SPECIFIC (ctx->old_fs);
	FatCluster cluster = fat_frag_to_cluster (ctx->old_fs, frag);
	FatClusterFlag flag;

	PED_ASSERT (cluster >= 2 && cluster < old_fs_info->cluster_count + 2,
	return 0);

	flag = fat_get_fragment_flag (ctx->old_fs, frag);
	switch (flag) {
	case FAT_FLAG_FREE:
	return 0;

	case FAT_FLAG_DIRECTORY:
	return 1;

	case FAT_FLAG_FILE:
	return fat_op_context_map_static_fragment (ctx, frag) == -1;

	case FAT_FLAG_BAD:
	return 0;
	}

	return 0;
	}

	static int
	search_next_fragment (FatOpContext* ctx)
	{
	FatSpecific* fs_info = FAT_SPECIFIC (ctx->old_fs);

	for (; ctx->buffer_offset < fs_info->frag_count; ctx->buffer_offset++) {
	if (needs_duplicating (ctx, ctx->buffer_offset))
	return 1;
	}
	return 0; /* all done! */
	}

	static int
	read_marked_fragments (FatOpContext* ctx, FatFragment length)
	{
	FatSpecific* fs_info = FAT_SPECIFIC (ctx->old_fs);
	int status;
	FatFragment i;

	ped_exception_fetch_all ();
	status = fat_read_fragments (ctx->old_fs, fs_info->buffer,
	ctx->buffer_offset, length);
	ped_exception_leave_all ();
	if (status)
	return 1;

	ped_exception_catch ();

	/* something bad happened, so read fragments one by one. (The error may
	have occurred on an unused fragment: who cares) */
	for (i = 0; i < length; i++) {
	if (ctx->buffer_map [i]) {
	if (!fat_read_fragment (ctx->old_fs,
	fs_info->buffer + i * fs_info->frag_size,
	ctx->buffer_offset + i))
	return 0;
	}
	}

	return 1;
	}

	static int
	fetch_fragments (FatOpContext* ctx)
	{
	FatSpecific* old_fs_info = FAT_SPECIFIC (ctx->old_fs);
	FatFragment fetch_length = 0;
	FatFragment frag;

	for (frag = 0; frag < ctx->buffer_frags; frag++)
	ctx->buffer_map [frag] = -1;

	for (frag = 0;
	frag < ctx->buffer_frags
	&& ctx->buffer_offset + frag < old_fs_info->frag_count;
	frag++) {
	if (needs_duplicating (ctx, ctx->buffer_offset + frag)) {
	ctx->buffer_map [frag] = 1;
	fetch_length = frag + 1;
	}
	}

	if (!read_marked_fragments (ctx, fetch_length))
	return 0;

	return 1;
	}

	/*****************************************************************************
	* here starts the write code. All assumes that ctx->buffer_map [first] and
	* ctx->buffer_map [last] are occupied by fragments that need to be duplicated.
	*****************************************************************************/

	/* finds the first fragment that is not going to get overwritten (that needs to
	get read in) */
	static FatFragment
	get_first_underlay (const FatOpContext* ctx, int first, int last)
	{
	int old;
	FatFragment new;

	PED_ASSERT (first <= last, return 0);

	new = ctx->buffer_map [first];
	for (old = first + 1; old <= last; old++) {
	if (ctx->buffer_map [old] == -1)
	continue;
	new++;
	if (ctx->buffer_map [old] != new)
	return new;
	}
	return -1;
	}

	/* finds the last fragment that is not going to get overwritten (that needs to
	get read in) */
	static FatFragment
	get_last_underlay (const FatOpContext* ctx, int first, int last)
	{
	int old;
	FatFragment new;

	PED_ASSERT (first <= last, return 0);

	new = ctx->buffer_map [last];
	for (old = last - 1; old >= first; old--) {
	if (ctx->buffer_map [old] == -1)
	continue;
	new--;
	if (ctx->buffer_map [old] != new)
	return new;
	}
	return -1;
	}

	/* "underlay" refers to the "static" fragments, that remain unchanged.
	* when writing large chunks at a time, we don't want to clobber these,
	* so we read them in, and write them back again. MUCH quicker that way.
	*/
	static int
	quick_group_write_read_underlay (FatOpContext* ctx, int first, int last)
	{
	FatSpecific* new_fs_info = FAT_SPECIFIC (ctx->new_fs);
	FatFragment first_underlay;
	FatFragment last_underlay;
	FatFragment underlay_length;

	PED_ASSERT (first <= last, return 0);

	first_underlay = get_first_underlay (ctx, first, last);
	if (first_underlay == -1)
	return 1;
	last_underlay = get_last_underlay (ctx, first, last);

	PED_ASSERT (first_underlay <= last_underlay, return 0);

	underlay_length = last_underlay - first_underlay + 1;
	if (!fat_read_fragments (ctx->new_fs,
	new_fs_info->buffer
	+ (first_underlay - ctx->buffer_map [first])
	* new_fs_info->frag_size,
	first_underlay,
	underlay_length))
	return 0;
	return 1;
	}

	/* quick_group_write() makes no attempt to recover from errors - just
	* does things fast. If there is an error, slow_group_write() is
	* called.
	* Note: we do syncing writes, to make sure there isn't any
	* error writing out. It's rather difficult recovering from errors
	* further on.
	*/
	static int
	quick_group_write (FatOpContext* ctx, int first, int last)
	{
	FatSpecific* old_fs_info = FAT_SPECIFIC (ctx->old_fs);
	FatSpecific* new_fs_info = FAT_SPECIFIC (ctx->new_fs);
	int active_length;
	int i;
	int offset;

	PED_ASSERT (first <= last, return 0);

	ped_exception_fetch_all ();
	if (!quick_group_write_read_underlay (ctx, first, last))
	goto error;

	for (i = first; i <= last; i++) {
	if (ctx->buffer_map [i] == -1)
	continue;

	offset = ctx->buffer_map [i] - ctx->buffer_map [first];
	memcpy (new_fs_info->buffer + offset * new_fs_info->frag_size,
	old_fs_info->buffer + i * new_fs_info->frag_size,
	new_fs_info->frag_size);
	}

	active_length = ctx->buffer_map [last] - ctx->buffer_map [first] + 1;
	if (!fat_write_sync_fragments (ctx->new_fs, new_fs_info->buffer,
	ctx->buffer_map [first], active_length))
	goto error;

	ped_exception_leave_all ();
	return 1;

	error:
	ped_exception_catch ();
	ped_exception_leave_all ();
	return 0;
	}

	/* Writes fragments out, one at a time, avoiding errors on redundant writes
	* on damaged parts of the disk we already know about. If there's an error
	* on one of the required fragments, it gets marked as bad, and a replacement
	* is found.
	*/
	static int
	slow_group_write (FatOpContext* ctx, int first, int last)
	{
	FatSpecific* old_fs_info = FAT_SPECIFIC (ctx->old_fs);
	FatSpecific* new_fs_info = FAT_SPECIFIC (ctx->new_fs);
	int i;

	PED_ASSERT (first <= last, return 0);

	for (i = first; i <= last; i++) {
	if (ctx->buffer_map [i] == -1)
	continue;

	while (!fat_write_sync_fragment (ctx->new_fs,
	old_fs_info->buffer + i * old_fs_info->frag_size,
	ctx->buffer_map [i])) {
	fat_table_set_bad (new_fs_info->fat,
	ctx->buffer_map [i]);
	ctx->buffer_map [i] = fat_table_alloc_cluster
	(new_fs_info->fat);
	if (ctx->buffer_map [i] == 0)
	return 0;
	}
	}
	return 1;
	}

	static int
	update_remap (FatOpContext* ctx, int first, int last)
	{
	int i;

	PED_ASSERT (first <= last, return 0);

	for (i = first; i <= last; i++) {
	if (ctx->buffer_map [i] == -1)
	continue;
	ctx->remap [ctx->buffer_offset + i] = ctx->buffer_map [i];
	}

	return 1;
	}

	static int
	group_write (FatOpContext* ctx, int first, int last)
	{
	PED_ASSERT (first <= last, return 0);

	if (!quick_group_write (ctx, first, last)) {
	if (!slow_group_write (ctx, first, last))
	return 0;
	}
	if (!update_remap (ctx, first, last))
	return 0;
	return 1;
	}

	/* assumes fragment size and new_fs's cluster size are equal */
	static int
	write_fragments (FatOpContext* ctx)
	{
	FatSpecific* old_fs_info = FAT_SPECIFIC (ctx->old_fs);
	FatSpecific* new_fs_info = FAT_SPECIFIC (ctx->new_fs);
	int group_start;
	int group_end = -1; /* shut gcc up! */
	FatFragment mapped_length;
	FatFragment i;
	FatCluster new_cluster;

	PED_ASSERT (ctx->buffer_offset < old_fs_info->frag_count, return 0);

	group_start = -1;
	for (i = 0; i < ctx->buffer_frags; i++) {
	if (ctx->buffer_map [i] == -1)
	continue;

	ctx->frags_duped++;

	new_cluster = fat_table_alloc_cluster (new_fs_info->fat);
	if (!new_cluster)
	return 0;
	fat_table_set_eof (new_fs_info->fat, new_cluster);
	ctx->buffer_map [i] = fat_cluster_to_frag (ctx->new_fs,
	new_cluster);

	if (group_start == -1)
	group_start = group_end = i;

	PED_ASSERT (ctx->buffer_map [i]
	>= ctx->buffer_map [group_start],
	return 0);

	mapped_length = ctx->buffer_map [i]
	- ctx->buffer_map [group_start] + 1;
	if (mapped_length <= ctx->buffer_frags) {
	group_end = i;
	} else {
	/* ran out of room in the buffer, so write this group,
	* and start a new one...
	*/
	if (!group_write (ctx, group_start, group_end))
	return 0;
	group_start = group_end = i;
	}
	}

	PED_ASSERT (group_start != -1, return 0);

	if (!group_write (ctx, group_start, group_end))
	return 0;
	return 1;
	}

	/* default all fragments to unmoved
	*/
	static void
	init_remap (FatOpContext* ctx)
	{
	FatSpecific* old_fs_info = FAT_SPECIFIC (ctx->old_fs);
	FatFragment i;

	for (i = 0; i < old_fs_info->frag_count; i++)
	ctx->remap[i] = fat_op_context_map_static_fragment (ctx, i);
	}

	static FatFragment
	count_frags_to_dup (FatOpContext* ctx)
	{
	FatSpecific* fs_info = FAT_SPECIFIC (ctx->old_fs);
	FatFragment i;
	FatFragment total;

	total = 0;

	for (i = 0; i < fs_info->frag_count; i++) {
	if (needs_duplicating (ctx, i))
	total++;
	}

	return total;
	}

	/* duplicates unreachable file clusters, and all directory clusters
	*/
	int
	fat_duplicate_clusters (FatOpContext* ctx, PedTimer* timer)
	{
	FatFragment total_frags_to_dup;

	init_remap (ctx);
	total_frags_to_dup = count_frags_to_dup (ctx);

	ped_timer_reset (timer);
	ped_timer_set_state_name (timer, "moving data");

	ctx->buffer_offset = 0;
	ctx->frags_duped = 0;
	while (search_next_fragment (ctx)) {
	ped_timer_update (
	timer, 1.0 * ctx->frags_duped / total_frags_to_dup);

	if (!fetch_fragments (ctx))
	return 0;
	if (!write_fragments (ctx))
	return 0;
	ctx->buffer_offset += ctx->buffer_frags;
	}

	ped_timer_update (timer, 1.0);
	return 1;
	}

	#endif /* !DISCOVER_ONLY */