/*
 * Copyright (C) 2001 Sistina Software
 *
 * This file is released under the LGPL.
 */

#include "pv_map.h"
#include "log.h"

#include <assert.h>

static int _create_maps(struct pool *mem, struct list *pvs, struct list *maps)
{
	struct list *tmp;
	struct physical_volume *pv;
	struct pv_map *pvm;

	list_iterate(tmp, pvs) {
		pv = &(list_item(tmp, struct pv_list)->pv);

		if (!(pvm = pool_zalloc(mem, sizeof(*pvm)))) {
			stack;
			return 0;
		}

		pvm->pv = pv;
		if (!(pvm->allocated_extents =
		      bitset_create(mem, pv->pe_count))) {
			stack;
			return 0;
		}

		list_init(&pvm->areas);
		list_add(maps, &pvm->list);
	}

	return 1;
}

static int _set_allocated(struct hash_table *hash,
			  struct physical_volume *pv, int pe)
{
	struct pv_map *pvm;

	if (!(pvm = (struct pv_map *) hash_lookup(hash, dev_name(pv->dev)))) {
		log_err("pv_map not present in hash table.");
		return 0;
	}

	/* sanity check */
	assert(!bit(pvm->allocated_extents, pe));

	bit_set(pvm->allocated_extents, pe);
	return 1;
}

static int _fill_bitsets(struct volume_group *vg, struct list *maps)
{
	struct list *lvh, *pvmh;
	struct logical_volume *lv;
	struct pv_map *pvm;
	uint32_t i, r = 0;
	struct hash_table *hash;

	if (!(hash = hash_table_create(128))) {
		log_err("Couldn't create hash table for pv maps.");
		return 0;
	}

	/* populate the hash table */
	list_iterate (pvmh, maps) {
		pvm = list_item(pvmh, struct pv_map);
		if (!hash_insert(hash, dev_name(pvm->pv->dev), pvm)) {
			stack;
			goto out;
		}
	}

	/* iterate through all the lv's setting bit's for used pe's */
	list_iterate (lvh, &vg->lvs) {
		lv = &(list_item(lvh, struct lv_list)->lv);

		list_iterate (segh, &lv->segments) {
			seg = list_item(segh, struct stripe_segment);

			for (i = 0; i < seg->len; i++) {
				if (!_set_allocated(hash,
					    seg->area[i % seg->stripes].pv,
					    seg->area[i % seg->stripes].pe +
						    (i / stripes))) {
					stack;
					goto out;
				}
			}
		}
	}
	r = 1;

 out:
	hash_table_destroy(hash);
	return r;
}

static int _create_single_area(struct pool *mem, struct pv_map *pvm,
			       uint32_t *extent)
{
	uint32_t e = *extent, b, count = pvm->pv->pe_count;
	struct pv_area *pva;

	while (e < count && bit(pvm->allocated_extents, e))
		e++;

	if (e == count) {
		*extent = e;
		return 1;
	}

	b = e++;

	while (e < count && !bit(pvm->allocated_extents, e))
		e++;

	if (!(pva = pool_zalloc(mem, sizeof(*pva)))) {
		stack;
		return 0;
	}

	pva->start = b;
	pva->count = e - b;
	list_add(&pvm->areas, &pva->list);
	*extent = e;

	return 1;
}

static int _create_areas(struct pool *mem, struct pv_map *pvm)
{
	uint32_t pe = 0;

	while (pe < pvm->pv->pe_count)
		if (!_create_single_area(mem, pvm, &pe)) {
			stack;
			return 0;
		}

	return 1;
}

static int _create_all_areas(struct pool *mem, struct list *maps)
{
	struct list *tmp;
	struct pv_map *pvm;

	list_iterate(tmp, maps) {
		pvm = list_item(tmp, struct pv_map);

		if (!_create_areas(mem, pvm)) {
			stack;
			return 0;
		}
	}

	return 1;
}

struct list *create_pv_maps(struct pool *mem, struct volume_group *vg,
			    struct list *pvs)
{
	struct list *maps = pool_zalloc(mem, sizeof(*maps));

	if (!maps) {
		stack;
		return NULL;
	}

	list_init(maps);

	if (!_create_maps(mem, pvs, maps)) {
		log_error("Couldn't create physical volume maps in %s",
			  vg->name);
		goto bad;
	}

	if (!_fill_bitsets(vg, maps)) {
		log_error("Couldn't fill extent allocation bitmaps in %s",
			  vg->name);
		goto bad;
	}

	if (!_create_all_areas(mem, maps)) {
		log_error("Couldn't create area maps in %s", vg->name);
		goto bad;
	}

	return maps;

      bad:
	pool_free(mem, maps);
	return NULL;
}