/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/bplist.h>
#include <sys/zfs_context.h>

void
bplist_init(bplist_t *bpl)
{
	bzero(bpl, sizeof (*bpl));
	mutex_init(&bpl->bpl_lock, NULL, MUTEX_DEFAULT, NULL);
	mutex_init(&bpl->bpl_q_lock, NULL, MUTEX_DEFAULT, NULL);
	list_create(&bpl->bpl_queue, sizeof (bplist_q_t),
	    offsetof(bplist_q_t, bpq_node));
}

void
bplist_fini(bplist_t *bpl)
{
	ASSERT(list_is_empty(&bpl->bpl_queue));
	list_destroy(&bpl->bpl_queue);
	mutex_destroy(&bpl->bpl_q_lock);
	mutex_destroy(&bpl->bpl_lock);
}

static int
bplist_hold(bplist_t *bpl)
{
	ASSERT(MUTEX_HELD(&bpl->bpl_lock));
	if (bpl->bpl_dbuf == NULL) {
		int err = dmu_bonus_hold(bpl->bpl_mos,
		    bpl->bpl_object, bpl, &bpl->bpl_dbuf);
		if (err)
			return (err);
		bpl->bpl_phys = bpl->bpl_dbuf->db_data;
	}
	return (0);
}

uint64_t
bplist_create(objset_t *mos, int blocksize, dmu_tx_t *tx)
{
	int size;

	size = spa_version(dmu_objset_spa(mos)) < SPA_VERSION_BPLIST_ACCOUNT ?
	    BPLIST_SIZE_V0 : sizeof (bplist_phys_t);

	return (dmu_object_alloc(mos, DMU_OT_BPLIST, blocksize,
	    DMU_OT_BPLIST_HDR, size, tx));
}

void
bplist_destroy(objset_t *mos, uint64_t object, dmu_tx_t *tx)
{
	VERIFY(dmu_object_free(mos, object, tx) == 0);
}

int
bplist_open(bplist_t *bpl, objset_t *mos, uint64_t object)
{
	dmu_object_info_t doi;
	int err;

	err = dmu_object_info(mos, object, &doi);
	if (err)
		return (err);

	mutex_enter(&bpl->bpl_lock);

	ASSERT(bpl->bpl_dbuf == NULL);
	ASSERT(bpl->bpl_phys == NULL);
	ASSERT(bpl->bpl_cached_dbuf == NULL);
	ASSERT(list_is_empty(&bpl->bpl_queue));
	ASSERT(object != 0);
	ASSERT3U(doi.doi_type, ==, DMU_OT_BPLIST);
	ASSERT3U(doi.doi_bonus_type, ==, DMU_OT_BPLIST_HDR);

	bpl->bpl_mos = mos;
	bpl->bpl_object = object;
	bpl->bpl_blockshift = highbit(doi.doi_data_block_size - 1);
	bpl->bpl_bpshift = bpl->bpl_blockshift - SPA_BLKPTRSHIFT;
	bpl->bpl_havecomp = (doi.doi_bonus_size == sizeof (bplist_phys_t));

	mutex_exit(&bpl->bpl_lock);
	return (0);
}

void
bplist_close(bplist_t *bpl)
{
	mutex_enter(&bpl->bpl_lock);

	ASSERT(list_is_empty(&bpl->bpl_queue));

	if (bpl->bpl_cached_dbuf) {
		dmu_buf_rele(bpl->bpl_cached_dbuf, bpl);
		bpl->bpl_cached_dbuf = NULL;
	}
	if (bpl->bpl_dbuf) {
		dmu_buf_rele(bpl->bpl_dbuf, bpl);
		bpl->bpl_dbuf = NULL;
		bpl->bpl_phys = NULL;
	}

	mutex_exit(&bpl->bpl_lock);
}

boolean_t
bplist_empty(bplist_t *bpl)
{
	boolean_t rv;

	if (bpl->bpl_object == 0)
		return (B_TRUE);

	mutex_enter(&bpl->bpl_lock);
	VERIFY(0 == bplist_hold(bpl)); /* XXX */
	rv = (bpl->bpl_phys->bpl_entries == 0);
	mutex_exit(&bpl->bpl_lock);

	return (rv);
}

static int
bplist_cache(bplist_t *bpl, uint64_t blkid)
{
	int err = 0;

	if (bpl->bpl_cached_dbuf == NULL ||
	    bpl->bpl_cached_dbuf->db_offset != (blkid << bpl->bpl_blockshift)) {
		if (bpl->bpl_cached_dbuf != NULL)
			dmu_buf_rele(bpl->bpl_cached_dbuf, bpl);
		err = dmu_buf_hold(bpl->bpl_mos,
		    bpl->bpl_object, blkid << bpl->bpl_blockshift,
		    bpl, &bpl->bpl_cached_dbuf);
		ASSERT(err || bpl->bpl_cached_dbuf->db_size ==
		    1ULL << bpl->bpl_blockshift);
	}
	return (err);
}

int
bplist_iterate(bplist_t *bpl, uint64_t *itorp, blkptr_t *bp)
{
	uint64_t blk, off;
	blkptr_t *bparray;
	int err;

	mutex_enter(&bpl->bpl_lock);

	err = bplist_hold(bpl);
	if (err) {
		mutex_exit(&bpl->bpl_lock);
		return (err);
	}

	if (*itorp >= bpl->bpl_phys->bpl_entries) {
		mutex_exit(&bpl->bpl_lock);
		return (ENOENT);
	}

	blk = *itorp >> bpl->bpl_bpshift;
	off = P2PHASE(*itorp, 1ULL << bpl->bpl_bpshift);

	err = bplist_cache(bpl, blk);
	if (err) {
		mutex_exit(&bpl->bpl_lock);
		return (err);
	}

	bparray = bpl->bpl_cached_dbuf->db_data;
	*bp = bparray[off];
	(*itorp)++;
	mutex_exit(&bpl->bpl_lock);
	return (0);
}

int
bplist_enqueue(bplist_t *bpl, const blkptr_t *bp, dmu_tx_t *tx)
{
	uint64_t blk, off;
	blkptr_t *bparray;
	int err;

	ASSERT(!BP_IS_HOLE(bp));
	mutex_enter(&bpl->bpl_lock);
	err = bplist_hold(bpl);
	if (err)
		return (err);

	blk = bpl->bpl_phys->bpl_entries >> bpl->bpl_bpshift;
	off = P2PHASE(bpl->bpl_phys->bpl_entries, 1ULL << bpl->bpl_bpshift);

	err = bplist_cache(bpl, blk);
	if (err) {
		mutex_exit(&bpl->bpl_lock);
		return (err);
	}

	dmu_buf_will_dirty(bpl->bpl_cached_dbuf, tx);
	bparray = bpl->bpl_cached_dbuf->db_data;
	bparray[off] = *bp;

	/* We never need the fill count. */
	bparray[off].blk_fill = 0;

	/* The bplist will compress better if we can leave off the checksum */
	if (!BP_GET_DEDUP(&bparray[off]))
		bzero(&bparray[off].blk_cksum, sizeof (bparray[off].blk_cksum));

	dmu_buf_will_dirty(bpl->bpl_dbuf, tx);
	bpl->bpl_phys->bpl_entries++;
	bpl->bpl_phys->bpl_bytes +=
	    bp_get_dsize_sync(dmu_objset_spa(bpl->bpl_mos), bp);
	if (bpl->bpl_havecomp) {
		bpl->bpl_phys->bpl_comp += BP_GET_PSIZE(bp);
		bpl->bpl_phys->bpl_uncomp += BP_GET_UCSIZE(bp);
	}
	mutex_exit(&bpl->bpl_lock);

	return (0);
}

void
bplist_enqueue_cb(void *bpl, const blkptr_t *bp, dmu_tx_t *tx)
{
	VERIFY(bplist_enqueue(bpl, bp, tx) == 0);
}

/*
 * Deferred entry; will be processed later by bplist_sync().
 */
void
bplist_enqueue_deferred(bplist_t *bpl, const blkptr_t *bp)
{
	bplist_q_t *bpq = kmem_alloc(sizeof (*bpq), KM_SLEEP);

	ASSERT(!BP_IS_HOLE(bp));
	mutex_enter(&bpl->bpl_q_lock);
	bpq->bpq_blk = *bp;
	list_insert_tail(&bpl->bpl_queue, bpq);
	mutex_exit(&bpl->bpl_q_lock);
}

void
bplist_sync(bplist_t *bpl, bplist_sync_cb_t *func, void *arg, dmu_tx_t *tx)
{
	bplist_q_t *bpq;

	mutex_enter(&bpl->bpl_q_lock);
	while (bpq = list_head(&bpl->bpl_queue)) {
		list_remove(&bpl->bpl_queue, bpq);
		mutex_exit(&bpl->bpl_q_lock);
		func(arg, &bpq->bpq_blk, tx);
		kmem_free(bpq, sizeof (*bpq));
		mutex_enter(&bpl->bpl_q_lock);
	}
	mutex_exit(&bpl->bpl_q_lock);
}

void
bplist_vacate(bplist_t *bpl, dmu_tx_t *tx)
{
	mutex_enter(&bpl->bpl_lock);
	ASSERT(list_is_empty(&bpl->bpl_queue));
	VERIFY(0 == bplist_hold(bpl));
	dmu_buf_will_dirty(bpl->bpl_dbuf, tx);
	VERIFY(0 == dmu_free_range(bpl->bpl_mos,
	    bpl->bpl_object, 0, -1ULL, tx));
	bpl->bpl_phys->bpl_entries = 0;
	bpl->bpl_phys->bpl_bytes = 0;
	if (bpl->bpl_havecomp) {
		bpl->bpl_phys->bpl_comp = 0;
		bpl->bpl_phys->bpl_uncomp = 0;
	}
	mutex_exit(&bpl->bpl_lock);
}

int
bplist_space(bplist_t *bpl, uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
{
	int err;

	mutex_enter(&bpl->bpl_lock);

	err = bplist_hold(bpl);
	if (err) {
		mutex_exit(&bpl->bpl_lock);
		return (err);
	}

	*usedp = bpl->bpl_phys->bpl_bytes;
	if (bpl->bpl_havecomp) {
		*compp = bpl->bpl_phys->bpl_comp;
		*uncompp = bpl->bpl_phys->bpl_uncomp;
	}
	mutex_exit(&bpl->bpl_lock);

	if (!bpl->bpl_havecomp) {
		uint64_t itor = 0, comp = 0, uncomp = 0;
		blkptr_t bp;

		while ((err = bplist_iterate(bpl, &itor, &bp)) == 0) {
			comp += BP_GET_PSIZE(&bp);
			uncomp += BP_GET_UCSIZE(&bp);
		}
		if (err == ENOENT)
			err = 0;
		*compp = comp;
		*uncompp = uncomp;
	}

	return (err);
}

/*
 * Return (in *dsizep) the amount of space on the deadlist which is:
 * mintxg < blk_birth <= maxtxg
 */
int
bplist_space_birthrange(bplist_t *bpl, uint64_t mintxg, uint64_t maxtxg,
    uint64_t *dsizep)
{
	uint64_t size = 0;
	uint64_t itor = 0;
	blkptr_t bp;
	int err;

	/*
	 * As an optimization, if they want the whole txg range, just
	 * get bpl_bytes rather than iterating over the bps.
	 */
	if (mintxg < TXG_INITIAL && maxtxg == UINT64_MAX) {
		mutex_enter(&bpl->bpl_lock);
		err = bplist_hold(bpl);
		if (err == 0)
			*dsizep = bpl->bpl_phys->bpl_bytes;
		mutex_exit(&bpl->bpl_lock);
		return (err);
	}

	while ((err = bplist_iterate(bpl, &itor, &bp)) == 0) {
		if (bp.blk_birth > mintxg && bp.blk_birth <= maxtxg) {
			size += bp_get_dsize(dmu_objset_spa(bpl->bpl_mos), &bp);
		}
	}
	if (err == ENOENT)
		err = 0;
	*dsizep = size;
	return (err);
}