/*
 * Copyright (C) 2012 STRATO.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * 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., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include "qgroup.h"
#include <sys/ioctl.h>
#include "kernel-shared/ctree.h"
#include "ioctl.h"
#include "common/utils.h"
#include "common/units.h"
#include <errno.h>

#define BTRFS_QGROUP_NFILTERS_INCREASE (2 * BTRFS_QGROUP_FILTER_MAX)
#define BTRFS_QGROUP_NCOMPS_INCREASE (2 * BTRFS_QGROUP_COMP_MAX)

struct qgroup_lookup {
	struct rb_root root;
};

struct btrfs_qgroup {
	struct rb_node rb_node;
	struct rb_node sort_node;
	/*
	 *all_parent_node is used to
	 *filter a qgroup's all parent
	 */
	struct rb_node all_parent_node;
	u64 qgroupid;

	/*
	 * info_item
	 */
	struct btrfs_qgroup_info info;

	/*
	 *limit_item
	 */
	struct btrfs_qgroup_limit limit;

	/*qgroups this group is member of*/
	struct list_head qgroups;
	/*qgroups that are members of this group*/
	struct list_head members;
};

/*
 * glue structure to represent the relations
 * between qgroups
 */
struct btrfs_qgroup_list {
	struct list_head next_qgroup;
	struct list_head next_member;
	struct btrfs_qgroup *qgroup;
	struct btrfs_qgroup *member;
};

/*
 * qgroupid,rfer,excl default to set
 */
static struct {
	char *name;
	char *column_name;
	int need_print;
	unsigned unit_mode;
	int max_len;
} btrfs_qgroup_columns[] = {
	{
		.name		= "qgroupid",
		.column_name	= "Qgroupid",
		.need_print	= 1,
		.unit_mode	= 0,
		.max_len	= 8,
	},
	{
		.name		= "rfer",
		.column_name	= "Rfer",
		.need_print	= 1,
		.unit_mode	= UNITS_DEFAULT,
		.max_len	= 12,
	},
	{
		.name		= "excl",
		.column_name	= "Excl",
		.need_print	= 1,
		.unit_mode	= UNITS_DEFAULT,
		.max_len	= 12,
	},
	{	.name		= "max_rfer",
		.column_name	= "Max_rfer",
		.need_print	= 0,
		.unit_mode	= UNITS_DEFAULT,
		.max_len	= 12,
	},
	{
		.name		= "max_excl",
		.column_name	= "Max_excl",
		.need_print	= 0,
		.unit_mode	= UNITS_DEFAULT,
		.max_len	= 12,
	},
	{
		.name		= "parent",
		.column_name	= "Parent",
		.need_print	= 0,
		.unit_mode	= 0,
		.max_len	= 7,
	},
	{
		.name		= "child",
		.column_name	= "Child",
		.need_print	= 0,
		.unit_mode	= 0,
		.max_len	= 5,
	},
	{
		.name		= NULL,
		.column_name	= NULL,
		.need_print	= 0,
		.unit_mode	= 0,
	},
};

static btrfs_qgroup_filter_func all_filter_funcs[];
static btrfs_qgroup_comp_func all_comp_funcs[];

void btrfs_qgroup_setup_print_column(enum btrfs_qgroup_column_enum column)
{
	int i;

	ASSERT(0 <= column && column <= BTRFS_QGROUP_ALL);

	if (column < BTRFS_QGROUP_ALL) {
		btrfs_qgroup_columns[column].need_print = 1;
		return;
	}
	for (i = 0; i < BTRFS_QGROUP_ALL; i++)
		btrfs_qgroup_columns[i].need_print = 1;
}

void btrfs_qgroup_setup_units(unsigned unit_mode)
{
	btrfs_qgroup_columns[BTRFS_QGROUP_RFER].unit_mode = unit_mode;
	btrfs_qgroup_columns[BTRFS_QGROUP_EXCL].unit_mode = unit_mode;
	btrfs_qgroup_columns[BTRFS_QGROUP_MAX_RFER].unit_mode = unit_mode;
	btrfs_qgroup_columns[BTRFS_QGROUP_MAX_EXCL].unit_mode = unit_mode;
}

static int print_parent_column(struct btrfs_qgroup *qgroup)
{
	struct btrfs_qgroup_list *list = NULL;
	int len = 0;

	list_for_each_entry(list, &qgroup->qgroups, next_qgroup) {
		len += printf("%llu/%llu",
			      btrfs_qgroup_level(list->qgroup->qgroupid),
			      btrfs_qgroup_subvid(list->qgroup->qgroupid));
		if (!list_is_last(&list->next_qgroup, &qgroup->qgroups))
			len += printf(",");
	}
	if (list_empty(&qgroup->qgroups))
		len += printf("---");

	return len;
}

static int print_child_column(struct btrfs_qgroup *qgroup)
{
	struct btrfs_qgroup_list *list = NULL;
	int len = 0;

	list_for_each_entry(list, &qgroup->members, next_member) {
		len += printf("%llu/%llu",
			      btrfs_qgroup_level(list->member->qgroupid),
			      btrfs_qgroup_subvid(list->member->qgroupid));
		if (!list_is_last(&list->next_member, &qgroup->members))
			len += printf(",");
	}
	if (list_empty(&qgroup->members))
		len += printf("---");

	return len;
}

static int print_u64(u64 value, int unit_mode, int max_len)
{
	return printf("%*s", max_len, pretty_size_mode(value, unit_mode));
}

static void print_qgroup_column_add_blank(enum btrfs_qgroup_column_enum column,
					  int len)
{
	len = btrfs_qgroup_columns[column].max_len - len;
	while (len--)
		printf(" ");
}

static void print_qgroup_column(struct btrfs_qgroup *qgroup,
				enum btrfs_qgroup_column_enum column)
{
	int len;
	int unit_mode = btrfs_qgroup_columns[column].unit_mode;
	int max_len = btrfs_qgroup_columns[column].max_len;

	ASSERT(0 <= column && column < BTRFS_QGROUP_ALL);

	switch (column) {

	case BTRFS_QGROUP_QGROUPID:
		len = printf("%llu/%llu",
			     btrfs_qgroup_level(qgroup->qgroupid),
			     btrfs_qgroup_subvid(qgroup->qgroupid));
		print_qgroup_column_add_blank(BTRFS_QGROUP_QGROUPID, len);
		break;
	case BTRFS_QGROUP_RFER:
		len = print_u64(qgroup->info.referenced, unit_mode, max_len);
		break;
	case BTRFS_QGROUP_EXCL:
		len = print_u64(qgroup->info.exclusive, unit_mode, max_len);
		break;
	case BTRFS_QGROUP_PARENT:
		len = print_parent_column(qgroup);
		print_qgroup_column_add_blank(BTRFS_QGROUP_PARENT, len);
		break;
	case BTRFS_QGROUP_MAX_RFER:
		if (qgroup->limit.flags & BTRFS_QGROUP_LIMIT_MAX_RFER)
			len = print_u64(qgroup->limit.max_referenced,
					unit_mode, max_len);
		else
			len = printf("%*s", max_len, "none");
		break;
	case BTRFS_QGROUP_MAX_EXCL:
		if (qgroup->limit.flags & BTRFS_QGROUP_LIMIT_MAX_EXCL)
			len = print_u64(qgroup->limit.max_exclusive,
					unit_mode, max_len);
		else
			len = printf("%*s", max_len, "none");
		break;
	case BTRFS_QGROUP_CHILD:
		len = print_child_column(qgroup);
		print_qgroup_column_add_blank(BTRFS_QGROUP_CHILD, len);
		break;
	default:
		break;
	}
}

static void print_single_qgroup_table(struct btrfs_qgroup *qgroup)
{
	int i;

	for (i = 0; i < BTRFS_QGROUP_ALL; i++) {
		if (!btrfs_qgroup_columns[i].need_print)
			continue;
		print_qgroup_column(qgroup, i);

		if (i != BTRFS_QGROUP_ALL - 1)
			printf(" ");
	}
	printf("\n");
}

static void print_table_head(void)
{
	int i;
	int len;
	int max_len;

	for (i = 0; i < BTRFS_QGROUP_ALL; i++) {
		max_len = btrfs_qgroup_columns[i].max_len;
		if (!btrfs_qgroup_columns[i].need_print)
			continue;
		if ((i == BTRFS_QGROUP_QGROUPID) | (i == BTRFS_QGROUP_PARENT) |
			(i == BTRFS_QGROUP_CHILD))
			printf("%-*s", max_len, btrfs_qgroup_columns[i].name);
		else
			printf("%*s", max_len, btrfs_qgroup_columns[i].name);
		printf(" ");
	}
	printf("\n");
	for (i = 0; i < BTRFS_QGROUP_ALL; i++) {
		max_len = btrfs_qgroup_columns[i].max_len;
		if (!btrfs_qgroup_columns[i].need_print)
			continue;
		if ((i == BTRFS_QGROUP_QGROUPID) | (i == BTRFS_QGROUP_PARENT) |
			(i == BTRFS_QGROUP_CHILD)) {
			len = strlen(btrfs_qgroup_columns[i].name);
			while (len--)
				printf("-");
			len = max_len - strlen(btrfs_qgroup_columns[i].name);
			while (len--)
				printf(" ");
		} else {
			len = max_len - strlen(btrfs_qgroup_columns[i].name);
			while (len--)
				printf(" ");
			len = strlen(btrfs_qgroup_columns[i].name);
			while (len--)
				printf("-");
		}
		printf(" ");
	}
	printf("\n");
}

static void qgroup_lookup_init(struct qgroup_lookup *tree)
{
	tree->root.rb_node = NULL;
}

static int comp_entry_with_qgroupid(struct btrfs_qgroup *entry1,
				    struct btrfs_qgroup *entry2,
				    int is_descending)
{

	int ret;

	if (entry1->qgroupid > entry2->qgroupid)
		ret = 1;
	else if (entry1->qgroupid < entry2->qgroupid)
		ret = -1;
	else
		ret = 0;

	return is_descending ? -ret : ret;
}

static int comp_entry_with_rfer(struct btrfs_qgroup *entry1,
				struct btrfs_qgroup *entry2,
				int is_descending)
{
	int ret;

	if (entry1->info.referenced > entry2->info.referenced)
		ret = 1;
	else if (entry1->info.referenced < entry2->info.referenced)
		ret = -1;
	else
		ret = 0;

	return is_descending ? -ret : ret;
}

static int comp_entry_with_excl(struct btrfs_qgroup *entry1,
				struct btrfs_qgroup *entry2,
				int is_descending)
{
	int ret;

	if (entry1->info.exclusive > entry2->info.exclusive)
		ret = 1;
	else if (entry1->info.exclusive < entry2->info.exclusive)
		ret = -1;
	else
		ret = 0;

	return is_descending ? -ret : ret;
}

static int comp_entry_with_max_rfer(struct btrfs_qgroup *entry1,
				    struct btrfs_qgroup *entry2,
				    int is_descending)
{
	int ret;

	if (entry1->limit.max_referenced > entry2->limit.max_referenced)
		ret = 1;
	else if (entry1->limit.max_referenced < entry2->limit.max_referenced)
		ret = -1;
	else
		ret = 0;

	return is_descending ? -ret : ret;
}

static int comp_entry_with_max_excl(struct btrfs_qgroup *entry1,
				    struct btrfs_qgroup *entry2,
				    int is_descending)
{
	int ret;

	if (entry1->limit.max_exclusive > entry2->limit.max_exclusive)
		ret = 1;
	else if (entry1->limit.max_exclusive < entry2->limit.max_exclusive)
		ret = -1;
	else
		ret = 0;

	return is_descending ? -ret : ret;
}

static btrfs_qgroup_comp_func all_comp_funcs[] = {
	[BTRFS_QGROUP_COMP_QGROUPID]	= comp_entry_with_qgroupid,
	[BTRFS_QGROUP_COMP_RFER]	= comp_entry_with_rfer,
	[BTRFS_QGROUP_COMP_EXCL]	= comp_entry_with_excl,
	[BTRFS_QGROUP_COMP_MAX_RFER]	= comp_entry_with_max_rfer,
	[BTRFS_QGROUP_COMP_MAX_EXCL]	= comp_entry_with_max_excl
};

static char *all_sort_items[] = {
	[BTRFS_QGROUP_COMP_QGROUPID]	= "qgroupid",
	[BTRFS_QGROUP_COMP_RFER]	= "rfer",
	[BTRFS_QGROUP_COMP_EXCL]	= "excl",
	[BTRFS_QGROUP_COMP_MAX_RFER]	= "max_rfer",
	[BTRFS_QGROUP_COMP_MAX_EXCL]	= "max_excl",
	[BTRFS_QGROUP_COMP_MAX]		= NULL,
};

static int  btrfs_qgroup_get_sort_item(char *sort_name)
{
	int i;

	for (i = 0; i < BTRFS_QGROUP_COMP_MAX; i++) {
		if (strcmp(sort_name, all_sort_items[i]) == 0)
			return i;
	}
	return -1;
}

struct btrfs_qgroup_comparer_set *btrfs_qgroup_alloc_comparer_set(void)
{
	struct btrfs_qgroup_comparer_set *set;
	int size;
	size = sizeof(struct btrfs_qgroup_comparer_set) +
	       BTRFS_QGROUP_NCOMPS_INCREASE *
	       sizeof(struct btrfs_qgroup_comparer);
	set = calloc(1, size);
	if (!set) {
		error("memory allocation failed");
		exit(1);
	}

	set->total = BTRFS_QGROUP_NCOMPS_INCREASE;

	return set;
}

int btrfs_qgroup_setup_comparer(struct btrfs_qgroup_comparer_set  **comp_set,
				enum btrfs_qgroup_comp_enum comparer,
				int is_descending)
{
	struct btrfs_qgroup_comparer_set *set = *comp_set;
	int size;

	ASSERT(set != NULL);
	ASSERT(comparer < BTRFS_QGROUP_COMP_MAX);
	ASSERT(set->ncomps <= set->total);

	if (set->ncomps == set->total) {
		void *tmp;

		size = set->total + BTRFS_QGROUP_NCOMPS_INCREASE;
		size = sizeof(*set) +
		       size * sizeof(struct btrfs_qgroup_comparer);
		tmp = set;
		set = realloc(set, size);
		if (!set) {
			free(tmp);
			return -ENOMEM;
		}

		memset(&set->comps[set->total], 0,
		       BTRFS_QGROUP_NCOMPS_INCREASE *
		       sizeof(struct btrfs_qgroup_comparer));
		set->total += BTRFS_QGROUP_NCOMPS_INCREASE;
		*comp_set = set;
	}

	ASSERT(set->comps[set->ncomps].comp_func == NULL);

	set->comps[set->ncomps].comp_func = all_comp_funcs[comparer];
	set->comps[set->ncomps].is_descending = is_descending;
	set->ncomps++;
	return 0;
}

static int sort_comp(struct btrfs_qgroup *entry1, struct btrfs_qgroup *entry2,
		     struct btrfs_qgroup_comparer_set *set)
{
	int qgroupid_compared = 0;
	int i, ret = 0;

	if (!set || !set->ncomps)
		goto comp_qgroupid;

	for (i = 0; i < set->ncomps; i++) {
		if (!set->comps[i].comp_func)
			break;

		ret = set->comps[i].comp_func(entry1, entry2,
					      set->comps[i].is_descending);
		if (ret)
			return ret;

		if (set->comps[i].comp_func == comp_entry_with_qgroupid)
			qgroupid_compared = 1;
	}

	if (!qgroupid_compared) {
comp_qgroupid:
		ret = comp_entry_with_qgroupid(entry1, entry2, 0);
	}

	return ret;
}

/*
 * insert a new root into the tree.  returns the existing root entry
 * if one is already there.  qgroupid is used
 * as the key
 */
static int qgroup_tree_insert(struct qgroup_lookup *root_tree,
			      struct btrfs_qgroup *ins)
{

	struct rb_node **p = &root_tree->root.rb_node;
	struct rb_node *parent = NULL;
	struct btrfs_qgroup *curr;
	int ret;

	while (*p) {
		parent = *p;
		curr = rb_entry(parent, struct btrfs_qgroup, rb_node);

		ret = comp_entry_with_qgroupid(ins, curr, 0);
		if (ret < 0)
			p = &(*p)->rb_left;
		else if (ret > 0)
			p = &(*p)->rb_right;
		else
			return -EEXIST;
	}
	rb_link_node(&ins->rb_node, parent, p);
	rb_insert_color(&ins->rb_node, &root_tree->root);
	return 0;
}

/*
 *find a given qgroupid in the tree. We return the smallest one,
 *rb_next can be used to move forward looking for more if required
 */
static struct btrfs_qgroup *qgroup_tree_search(struct qgroup_lookup *root_tree,
					       u64 qgroupid)
{
	struct rb_node *n = root_tree->root.rb_node;
	struct btrfs_qgroup *entry;
	struct btrfs_qgroup tmp;
	int ret;

	tmp.qgroupid = qgroupid;

	while (n) {
		entry = rb_entry(n, struct btrfs_qgroup, rb_node);

		ret = comp_entry_with_qgroupid(&tmp, entry, 0);
		if (ret < 0)
			n = n->rb_left;
		else if (ret > 0)
			n = n->rb_right;
		else
			return entry;

	}
	return NULL;
}

/*
 * Lookup or insert btrfs_qgroup into qgroup_lookup.
 *
 * Search a btrfs_qgroup with @qgroupid from the @qgroup_lookup. If not found,
 * initialize a btrfs_qgroup with the given qgroupid and insert it to the
 * @qgroup_lookup.
 *
 * Return the pointer to the btrfs_qgroup if found or if inserted successfully.
 * Return ERR_PTR if any error occurred.
 */
static struct btrfs_qgroup *get_or_add_qgroup(
		struct qgroup_lookup *qgroup_lookup, u64 qgroupid)
{
	struct btrfs_qgroup *bq;
	int ret;

	bq = qgroup_tree_search(qgroup_lookup, qgroupid);
	if (bq)
		return bq;

	bq = calloc(1, sizeof(*bq));
	if (!bq) {
		error("memory allocation failed");
		return ERR_PTR(-ENOMEM);
	}

	bq->qgroupid = qgroupid;
	INIT_LIST_HEAD(&bq->qgroups);
	INIT_LIST_HEAD(&bq->members);

	ret = qgroup_tree_insert(qgroup_lookup, bq);
	if (ret) {
		errno = -ret;
		error("failed to insert %llu into tree: %m",
		       (unsigned long long)bq->qgroupid);
		free(bq);
		return ERR_PTR(ret);
	}

	return bq;
}

static int update_qgroup_info(struct qgroup_lookup *qgroup_lookup, u64 qgroupid,
			      struct btrfs_qgroup_info_item *info)
{
	struct btrfs_qgroup *bq;

	bq = get_or_add_qgroup(qgroup_lookup, qgroupid);
	if (IS_ERR_OR_NULL(bq))
		return PTR_ERR(bq);

	bq->info.generation = btrfs_stack_qgroup_info_generation(info);
	bq->info.referenced = btrfs_stack_qgroup_info_referenced(info);
	bq->info.referenced_compressed =
			btrfs_stack_qgroup_info_referenced_compressed(info);
	bq->info.exclusive = btrfs_stack_qgroup_info_exclusive(info);
	bq->info.exclusive_compressed =
			btrfs_stack_qgroup_info_exclusive_compressed(info);

	return 0;
}

static int update_qgroup_limit(struct qgroup_lookup *qgroup_lookup,
			       u64 qgroupid,
			       struct btrfs_qgroup_limit_item *limit)
{
	struct btrfs_qgroup *bq;

	bq = get_or_add_qgroup(qgroup_lookup, qgroupid);
	if (IS_ERR_OR_NULL(bq))
		return PTR_ERR(bq);

	bq->limit.flags = btrfs_stack_qgroup_limit_flags(limit);
	bq->limit.max_referenced =
			btrfs_stack_qgroup_limit_max_referenced(limit);
	bq->limit.max_exclusive =
			btrfs_stack_qgroup_limit_max_exclusive(limit);
	bq->limit.rsv_referenced =
			btrfs_stack_qgroup_limit_rsv_referenced(limit);
	bq->limit.rsv_exclusive = btrfs_stack_qgroup_limit_rsv_exclusive(limit);

	return 0;
}

static int update_qgroup_relation(struct qgroup_lookup *qgroup_lookup,
				  u64 child_id, u64 parent_id)
{
	struct btrfs_qgroup *child;
	struct btrfs_qgroup *parent;
	struct btrfs_qgroup_list *list;

	child = qgroup_tree_search(qgroup_lookup, child_id);
	if (!child) {
		error("cannot find the qgroup %llu/%llu",
		      btrfs_qgroup_level(child_id),
		      btrfs_qgroup_subvid(child_id));
		return -ENOENT;
	}

	parent = qgroup_tree_search(qgroup_lookup, parent_id);
	if (!parent) {
		error("cannot find the qgroup %llu/%llu",
		      btrfs_qgroup_level(parent_id),
		      btrfs_qgroup_subvid(parent_id));
		return -ENOENT;
	}

	list = malloc(sizeof(*list));
	if (!list) {
		error("memory allocation failed");
		return -ENOMEM;
	}

	list->qgroup = parent;
	list->member = child;
	list_add_tail(&list->next_qgroup, &child->qgroups);
	list_add_tail(&list->next_member, &parent->members);

	return 0;
}

static void __free_btrfs_qgroup(struct btrfs_qgroup *bq)
{
	struct btrfs_qgroup_list *list;
	while (!list_empty(&bq->qgroups)) {
		list = list_entry((&bq->qgroups)->next,
				  struct btrfs_qgroup_list,
				  next_qgroup);
		list_del(&list->next_qgroup);
		list_del(&list->next_member);
		free(list);
	}
	while (!list_empty(&bq->members)) {
		list = list_entry((&bq->members)->next,
				  struct btrfs_qgroup_list,
				  next_member);
		list_del(&list->next_qgroup);
		list_del(&list->next_member);
		free(list);
	}
	free(bq);
}

static void __free_all_qgroups(struct qgroup_lookup *root_tree)
{
	struct btrfs_qgroup *entry;
	struct rb_node *n;

	n = rb_first(&root_tree->root);
	while (n) {
		entry = rb_entry(n, struct btrfs_qgroup, rb_node);
		rb_erase(n, &root_tree->root);
		__free_btrfs_qgroup(entry);

		n = rb_first(&root_tree->root);
	}
}

static int filter_all_parent_insert(struct qgroup_lookup *sort_tree,
				    struct btrfs_qgroup *bq)
{
	struct rb_node **p = &sort_tree->root.rb_node;
	struct rb_node *parent = NULL;
	struct btrfs_qgroup *curr;
	int ret;

	while (*p) {
		parent = *p;
		curr = rb_entry(parent, struct btrfs_qgroup, all_parent_node);

		ret = comp_entry_with_qgroupid(bq, curr, 0);
		if (ret < 0)
			p = &(*p)->rb_left;
		else if (ret > 0)
			p = &(*p)->rb_right;
		else
			return -EEXIST;
	}
	rb_link_node(&bq->all_parent_node, parent, p);
	rb_insert_color(&bq->all_parent_node, &sort_tree->root);
	return 0;
}

static int filter_by_parent(struct btrfs_qgroup *bq, u64 data)
{
	struct btrfs_qgroup *qgroup =
		(struct btrfs_qgroup *)(unsigned long)data;

	if (data == 0)
		return 0;
	if (qgroup->qgroupid == bq->qgroupid)
		return 1;
	return 0;
}

static int filter_by_all_parent(struct btrfs_qgroup *bq, u64 data)
{
	struct qgroup_lookup lookup;
	struct qgroup_lookup *ql = &lookup;
	struct btrfs_qgroup_list *list;
	struct rb_node *n;
	struct btrfs_qgroup *qgroup =
			 (struct btrfs_qgroup *)(unsigned long)data;

	if (data == 0)
		return 0;
	if (bq->qgroupid == qgroup->qgroupid)
		return 1;

	qgroup_lookup_init(ql);
	filter_all_parent_insert(ql, qgroup);
	n = rb_first(&ql->root);
	while (n) {
		qgroup = rb_entry(n, struct btrfs_qgroup, all_parent_node);
		if (!list_empty(&qgroup->qgroups)) {
			list_for_each_entry(list, &qgroup->qgroups,
					    next_qgroup) {
				if ((list->qgroup)->qgroupid == bq->qgroupid)
					return 1;
				filter_all_parent_insert(ql, list->qgroup);
			}
		}
		rb_erase(n, &ql->root);
		n = rb_first(&ql->root);
	}
	return 0;
}

static btrfs_qgroup_filter_func all_filter_funcs[] = {
	[BTRFS_QGROUP_FILTER_PARENT]		= filter_by_parent,
	[BTRFS_QGROUP_FILTER_ALL_PARENT]	= filter_by_all_parent,
};

struct btrfs_qgroup_filter_set *btrfs_qgroup_alloc_filter_set(void)
{
	struct btrfs_qgroup_filter_set *set;
	int size;

	size = sizeof(struct btrfs_qgroup_filter_set) +
	       BTRFS_QGROUP_NFILTERS_INCREASE *
	       sizeof(struct btrfs_qgroup_filter);
	set = calloc(1, size);
	if (!set) {
		error("memory allocation failed");
		exit(1);
	}
	set->total = BTRFS_QGROUP_NFILTERS_INCREASE;

	return set;
}

int btrfs_qgroup_setup_filter(struct btrfs_qgroup_filter_set **filter_set,
			      enum btrfs_qgroup_filter_enum filter, u64 data)
{
	struct btrfs_qgroup_filter_set *set = *filter_set;
	int size;

	ASSERT(set != NULL);
	ASSERT(filter < BTRFS_QGROUP_FILTER_MAX);
	ASSERT(set->nfilters <= set->total);

	if (set->nfilters == set->total) {
		void *tmp;

		size = set->total + BTRFS_QGROUP_NFILTERS_INCREASE;
		size = sizeof(*set) + size * sizeof(struct btrfs_qgroup_filter);

		tmp = set;
		set = realloc(set, size);
		if (!set) {
			error("memory allocation failed");
			free(tmp);
			exit(1);
		}
		memset(&set->filters[set->total], 0,
		       BTRFS_QGROUP_NFILTERS_INCREASE *
		       sizeof(struct btrfs_qgroup_filter));
		set->total += BTRFS_QGROUP_NFILTERS_INCREASE;
		*filter_set = set;
	}

	ASSERT(set->filters[set->nfilters].filter_func == NULL);
	set->filters[set->nfilters].filter_func = all_filter_funcs[filter];
	set->filters[set->nfilters].data = data;
	set->nfilters++;
	return 0;
}

static int filter_qgroup(struct btrfs_qgroup *bq,
			 struct btrfs_qgroup_filter_set *set)
{
	int i, ret;

	if (!set || !set->nfilters)
		return 1;
	for (i = 0; i < set->nfilters; i++) {
		if (!set->filters[i].filter_func)
			break;
		ret = set->filters[i].filter_func(bq, set->filters[i].data);
		if (!ret)
			return 0;
	}
	return 1;
}

static void pre_process_filter_set(struct qgroup_lookup *lookup,
				   struct btrfs_qgroup_filter_set *set)
{
	int i;
	struct btrfs_qgroup *qgroup_for_filter = NULL;

	for (i = 0; i < set->nfilters; i++) {

		if (set->filters[i].filter_func == filter_by_all_parent
		    || set->filters[i].filter_func == filter_by_parent) {
			qgroup_for_filter = qgroup_tree_search(lookup,
					    set->filters[i].data);
			set->filters[i].data =
				 (u64)(unsigned long)qgroup_for_filter;
		}
	}
}

static int sort_tree_insert(struct qgroup_lookup *sort_tree,
			    struct btrfs_qgroup *bq,
			    struct btrfs_qgroup_comparer_set *comp_set)
{
	struct rb_node **p = &sort_tree->root.rb_node;
	struct rb_node *parent = NULL;
	struct btrfs_qgroup *curr;
	int ret;

	while (*p) {
		parent = *p;
		curr = rb_entry(parent, struct btrfs_qgroup, sort_node);

		ret = sort_comp(bq, curr, comp_set);
		if (ret < 0)
			p = &(*p)->rb_left;
		else if (ret > 0)
			p = &(*p)->rb_right;
		else
			return -EEXIST;
	}
	rb_link_node(&bq->sort_node, parent, p);
	rb_insert_color(&bq->sort_node, &sort_tree->root);
	return 0;
}

static void __update_columns_max_len(struct btrfs_qgroup *bq,
				     enum btrfs_qgroup_column_enum column)
{
	struct btrfs_qgroup_list *list = NULL;
	char tmp[100];
	int len;
	unsigned unit_mode = btrfs_qgroup_columns[column].unit_mode;

	ASSERT(0 <= column && column < BTRFS_QGROUP_ALL);

	switch (column) {

	case BTRFS_QGROUP_QGROUPID:
		sprintf(tmp, "%llu/%llu",
			btrfs_qgroup_level(bq->qgroupid),
			btrfs_qgroup_subvid(bq->qgroupid));
		len = strlen(tmp);
		if (btrfs_qgroup_columns[column].max_len < len)
			btrfs_qgroup_columns[column].max_len = len;
		break;
	case BTRFS_QGROUP_RFER:
		len = strlen(pretty_size_mode(bq->info.referenced, unit_mode));
		if (btrfs_qgroup_columns[column].max_len < len)
			btrfs_qgroup_columns[column].max_len = len;
		break;
	case BTRFS_QGROUP_EXCL:
		len = strlen(pretty_size_mode(bq->info.exclusive, unit_mode));
		if (btrfs_qgroup_columns[column].max_len < len)
			btrfs_qgroup_columns[column].max_len = len;
		break;
	case BTRFS_QGROUP_MAX_RFER:
		len = strlen(pretty_size_mode(bq->limit.max_referenced,
			     unit_mode));
		if (btrfs_qgroup_columns[column].max_len < len)
			btrfs_qgroup_columns[column].max_len = len;
		break;
	case BTRFS_QGROUP_MAX_EXCL:
		len = strlen(pretty_size_mode(bq->limit.max_exclusive,
			     unit_mode));
		if (btrfs_qgroup_columns[column].max_len < len)
			btrfs_qgroup_columns[column].max_len = len;
		break;
	case BTRFS_QGROUP_PARENT:
		len = 0;
		list_for_each_entry(list, &bq->qgroups, next_qgroup) {
			len += sprintf(tmp, "%llu/%llu",
				btrfs_qgroup_level(list->qgroup->qgroupid),
				btrfs_qgroup_subvid(list->qgroup->qgroupid));
			if (!list_is_last(&list->next_qgroup, &bq->qgroups))
				len += 1;
		}
		if (btrfs_qgroup_columns[column].max_len < len)
			btrfs_qgroup_columns[column].max_len = len;
		break;
	case BTRFS_QGROUP_CHILD:
		len = 0;
		list_for_each_entry(list, &bq->members, next_member) {
			len += sprintf(tmp, "%llu/%llu",
				btrfs_qgroup_level(list->member->qgroupid),
				btrfs_qgroup_subvid(list->member->qgroupid));
			if (!list_is_last(&list->next_member, &bq->members))
				len += 1;
		}
		if (btrfs_qgroup_columns[column].max_len < len)
			btrfs_qgroup_columns[column].max_len = len;
		break;
	default:
		break;
	}

}

static void update_columns_max_len(struct btrfs_qgroup *bq)
{
	int i;

	for (i = 0; i < BTRFS_QGROUP_ALL; i++) {
		if (!btrfs_qgroup_columns[i].need_print)
			continue;
		__update_columns_max_len(bq, i);
	}
}

static void __filter_and_sort_qgroups(struct qgroup_lookup *all_qgroups,
				 struct qgroup_lookup *sort_tree,
				 struct btrfs_qgroup_filter_set *filter_set,
				 struct btrfs_qgroup_comparer_set *comp_set)
{
	struct rb_node *n;
	struct btrfs_qgroup *entry;
	int ret;

	qgroup_lookup_init(sort_tree);
	pre_process_filter_set(all_qgroups, filter_set);

	n = rb_last(&all_qgroups->root);
	while (n) {
		entry = rb_entry(n, struct btrfs_qgroup, rb_node);

		ret = filter_qgroup(entry, filter_set);
		if (ret) {
			sort_tree_insert(sort_tree, entry, comp_set);

			update_columns_max_len(entry);
		}
		n = rb_prev(n);
	}
}

static inline void print_status_flag_warning(u64 flags)
{
	if (!(flags & BTRFS_QGROUP_STATUS_FLAG_ON))
		warning("quota disabled, qgroup data may be out of date");
	else if (flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN)
		warning("rescan is running, qgroup data may be incorrect");
	else if (flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT)
		warning("qgroup data inconsistent, rescan recommended");
}

static bool key_in_range(const struct btrfs_key *key,
			 const struct btrfs_ioctl_search_key *sk)
{
	if (key->objectid < sk->min_objectid ||
	    key->objectid > sk->max_objectid)
		return false;

	if (key->type < sk->min_type ||
	    key->type > sk->max_type)
		return false;

	if (key->offset < sk->min_offset ||
	    key->offset > sk->max_offset)
		return false;

	return true;
}

static int __qgroups_search(int fd, struct btrfs_ioctl_search_args *args,
			    struct qgroup_lookup *qgroup_lookup)
{
	int ret;
	struct btrfs_ioctl_search_key *sk = &args->key;
	struct btrfs_ioctl_search_key filter_key = args->key;
	struct btrfs_ioctl_search_header *sh;
	unsigned long off = 0;
	unsigned int i;
	struct btrfs_qgroup_status_item *si;
	struct btrfs_qgroup_info_item *info;
	struct btrfs_qgroup_limit_item *limit;
	u64 flags;
	u64 qgroupid;
	u64 child, parent;

	qgroup_lookup_init(qgroup_lookup);

	while (1) {
		ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, args);
		if (ret < 0) {
			if (errno == ENOENT)
				ret = -ENOTTY;
			else
				ret = -errno;
			break;
		}

		/* the ioctl returns the number of item it found in nr_items */
		if (sk->nr_items == 0)
			break;

		off = 0;
		/*
		 * for each item, pull the key out of the header and then
		 * read the root_ref item it contains
		 */
		for (i = 0; i < sk->nr_items; i++) {
			struct btrfs_key key;

			sh = (struct btrfs_ioctl_search_header *)(args->buf +
								  off);
			off += sizeof(*sh);

			key.objectid = btrfs_search_header_objectid(sh);
			key.type = btrfs_search_header_type(sh);
			key.offset = btrfs_search_header_offset(sh);

			if (!key_in_range(&key, &filter_key))
				goto next;

			switch (key.type) {
			case BTRFS_QGROUP_STATUS_KEY:
				si = (struct btrfs_qgroup_status_item *)
				     (args->buf + off);
				flags = btrfs_stack_qgroup_status_flags(si);

				print_status_flag_warning(flags);
				break;
			case BTRFS_QGROUP_INFO_KEY:
				qgroupid = key.offset;
				info = (struct btrfs_qgroup_info_item *)
				       (args->buf + off);

				ret = update_qgroup_info(qgroup_lookup,
							 qgroupid, info);
				break;
			case BTRFS_QGROUP_LIMIT_KEY:
				qgroupid = key.offset;
				limit = (struct btrfs_qgroup_limit_item *)
					(args->buf + off);

				ret = update_qgroup_limit(qgroup_lookup,
							  qgroupid, limit);
				break;
			case BTRFS_QGROUP_RELATION_KEY:
				child = key.offset;
				parent = key.objectid;

				if (parent <= child)
					break;

				ret = update_qgroup_relation(qgroup_lookup,
							     child, parent);
				break;
			default:
				return ret;
			}

			if (ret)
				return ret;

next:
			off += btrfs_search_header_len(sh);

			/*
			 * record the mins in sk so we can make sure the
			 * next search doesn't repeat this root
			 */
			sk->min_type = key.type;
			sk->min_offset = key.offset;
			sk->min_objectid = key.objectid;
		}
		sk->nr_items = 4096;
		/*
		 * this iteration is done, step forward one qgroup for the next
		 * ioctl
		 */
		if (sk->min_offset < (u64)-1)
			sk->min_offset++;
		else
			break;
	}

	return ret;
}

static int qgroups_search_all(int fd, struct qgroup_lookup *qgroup_lookup)
{
	struct btrfs_ioctl_search_args args = {
		.key = {
			.tree_id = BTRFS_QUOTA_TREE_OBJECTID,
			.max_type = BTRFS_QGROUP_RELATION_KEY,
			.min_type = BTRFS_QGROUP_STATUS_KEY,
			.max_objectid = (u64)-1,
			.max_offset = (u64)-1,
			.max_transid = (u64)-1,
			.nr_items = 4096,
		},
	};
	int ret;

	ret = __qgroups_search(fd, &args, qgroup_lookup);
	if (ret == -ENOTTY)
		error("can't list qgroups: quotas not enabled");
	else if (ret < 0)
		error("can't list qgroups: %s", strerror(-ret));
	return ret;
}

int btrfs_qgroup_query(int fd, u64 qgroupid, struct btrfs_qgroup_stats *stats)
{
	struct btrfs_ioctl_search_args args = {
		.key = {
			.tree_id = BTRFS_QUOTA_TREE_OBJECTID,
			.min_type = BTRFS_QGROUP_INFO_KEY,
			.max_type = BTRFS_QGROUP_LIMIT_KEY,
			.max_objectid = 0,
			.min_offset = qgroupid,
			.max_offset = qgroupid,
			.max_transid = (u64)-1,
			.nr_items = 4096,
		},
	};
	struct qgroup_lookup qgroup_lookup;
	struct btrfs_qgroup *qgroup;
	struct rb_node *n;
	int ret;

	ret = __qgroups_search(fd, &args, &qgroup_lookup);
	if (ret < 0)
		return ret;

	ret = -ENODATA;
	n = rb_first(&qgroup_lookup.root);
	if (n) {
		qgroup = rb_entry(n, struct btrfs_qgroup, rb_node);
		stats->qgroupid = qgroup->qgroupid;
		stats->info = qgroup->info;
		stats->limit = qgroup->limit;

		ret = 0;
	}

	__free_all_qgroups(&qgroup_lookup);
	return ret;
}

static void print_all_qgroups(struct qgroup_lookup *qgroup_lookup)
{

	struct rb_node *n;
	struct btrfs_qgroup *entry;

	print_table_head();

	n = rb_first(&qgroup_lookup->root);
	while (n) {
		entry = rb_entry(n, struct btrfs_qgroup, sort_node);
		print_single_qgroup_table(entry);
		n = rb_next(n);
	}
}

int btrfs_show_qgroups(int fd,
		       struct btrfs_qgroup_filter_set *filter_set,
		       struct btrfs_qgroup_comparer_set *comp_set)
{

	struct qgroup_lookup qgroup_lookup;
	struct qgroup_lookup sort_tree;
	int ret;

	ret = qgroups_search_all(fd, &qgroup_lookup);
	if (ret)
		return ret;
	__filter_and_sort_qgroups(&qgroup_lookup, &sort_tree,
				  filter_set, comp_set);
	print_all_qgroups(&sort_tree);

	__free_all_qgroups(&qgroup_lookup);
	return ret;
}

/*
 * Parse sort string and allocate new comparator.
 *
 * Return: 0 no errors while parsing
 *         1 parse error
 *        <0 other errors
 */
int btrfs_qgroup_parse_sort_string(const char *opt_arg,
				   struct btrfs_qgroup_comparer_set **comps)
{
	int order;
	int flag;
	char *p;
	char **ptr_argv;
	int what_to_sort;
	char *opt_tmp;
	int ret = 0, ret2;

	opt_tmp = strdup(opt_arg);
	if (!opt_tmp)
		return -ENOMEM;

	p = strtok(opt_tmp, ",");
	while (p) {
		flag = 0;
		ptr_argv = all_sort_items;

		while (*ptr_argv) {
			if (strcmp(*ptr_argv, p) == 0) {
				flag = 1;
				break;
			} else {
				p++;
				if (strcmp(*ptr_argv, p) == 0) {
					flag = 1;
					p--;
					break;
				}
				p--;
			}
			ptr_argv++;
		}

		if (flag == 0) {
			ret = 1;
			goto out;
		} else {
			if (*p == '+') {
				order = 0;
				p++;
			} else if (*p == '-') {
				order = 1;
				p++;
			} else
				order = 0;

			what_to_sort = btrfs_qgroup_get_sort_item(p);
			if (what_to_sort < 0) {
				ret = 1;
				goto out;
			}
			ret2 = btrfs_qgroup_setup_comparer(comps, what_to_sort,
					order);
			if (ret2 < 0) {
				ret = ret2;
				goto out;
			}
		}
		p = strtok(NULL, ",");
	}

out:
	free(opt_tmp);
	return ret;
}

int qgroup_inherit_size(struct btrfs_qgroup_inherit *p)
{
	return sizeof(*p) + sizeof(p->qgroups[0]) *
			    (p->num_qgroups + 2 * p->num_ref_copies +
			     2 * p->num_excl_copies);
}

static int
qgroup_inherit_realloc(struct btrfs_qgroup_inherit **inherit, int n, int pos)
{
	struct btrfs_qgroup_inherit *out;
	int nitems = 0;

	if (*inherit) {
		nitems = (*inherit)->num_qgroups +
			 (*inherit)->num_ref_copies +
			 (*inherit)->num_excl_copies;
	}

	out = calloc(sizeof(*out) + sizeof(out->qgroups[0]) * (nitems + n), 1);
	if (out == NULL) {
		error("not enough memory");
		return -ENOMEM;
	}

	if (*inherit) {
		struct btrfs_qgroup_inherit *i = *inherit;
		int s = sizeof(out->qgroups[0]);

		out->num_qgroups = i->num_qgroups;
		out->num_ref_copies = i->num_ref_copies;
		out->num_excl_copies = i->num_excl_copies;
		memcpy(out->qgroups, i->qgroups, pos * s);
		memcpy(out->qgroups + pos + n, i->qgroups + pos,
		       (nitems - pos) * s);
	}
	free(*inherit);
	*inherit = out;

	return 0;
}

int qgroup_inherit_add_group(struct btrfs_qgroup_inherit **inherit, char *arg)
{
	int ret;
	u64 qgroupid = parse_qgroupid(arg);
	int pos = 0;

	if (qgroupid == 0) {
		error("invalid qgroup specification, qgroupid must not 0");
		return -EINVAL;
	}

	if (*inherit)
		pos = (*inherit)->num_qgroups;
	ret = qgroup_inherit_realloc(inherit, 1, pos);
	if (ret)
		return ret;

	(*inherit)->qgroups[(*inherit)->num_qgroups++] = qgroupid;

	return 0;
}

int qgroup_inherit_add_copy(struct btrfs_qgroup_inherit **inherit, char *arg,
			    int type)
{
	int ret;
	u64 qgroup_src;
	u64 qgroup_dst;
	char *p;
	int pos = 0;

	p = strchr(arg, ':');
	if (!p) {
bad:
		error("invalid copy specification, missing separator :");
		return -EINVAL;
	}
	*p = 0;
	qgroup_src = parse_qgroupid(arg);
	qgroup_dst = parse_qgroupid(p + 1);
	*p = ':';

	if (!qgroup_src || !qgroup_dst)
		goto bad;

	if (*inherit)
		pos = (*inherit)->num_qgroups +
		      (*inherit)->num_ref_copies * 2 * type;

	ret = qgroup_inherit_realloc(inherit, 2, pos);
	if (ret)
		return ret;

	(*inherit)->qgroups[pos++] = qgroup_src;
	(*inherit)->qgroups[pos++] = qgroup_dst;

	if (!type)
		++(*inherit)->num_ref_copies;
	else
		++(*inherit)->num_excl_copies;

	return 0;
}