/*

 * 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 2009 Sun Microsystems, Inc.  All rights reserved.

 * Use is subject to license terms.

 */

#include <sys/dmu.h>

#include <sys/dmu_objset.h>

#include <sys/dmu_tx.h>

#include <sys/dnode.h>

uint64_t

dmu_object_alloc(objset_t *os, dmu_object_type_t ot, int blocksize,

    dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)

{

	objset_impl_t *osi = os->os;

	uint64_t object;

	uint64_t L2_dnode_count = DNODES_PER_BLOCK <<

	    (osi->os_meta_dnode->dn_indblkshift - SPA_BLKPTRSHIFT);

	dnode_t *dn = NULL;

	int restarted = B_FALSE;

	mutex_enter(&osi->os_obj_lock);

	for (;;) {

		object = osi->os_obj_next;

		/*

		 * Each time we polish off an L2 bp worth of dnodes

		 * (2^13 objects), move to another L2 bp that's still

		 * reasonably sparse (at most 1/4 full).  Look from the

		 * beginning once, but after that keep looking from here.

		 * If we can't find one, just keep going from here.

		 */

		if (P2PHASE(object, L2_dnode_count) == 0) {

			uint64_t offset = restarted ? object << DNODE_SHIFT : 0;

			int error = dnode_next_offset(osi->os_meta_dnode,

			    DNODE_FIND_HOLE,

			    &offset, 2, DNODES_PER_BLOCK >> 2, 0);

			restarted = B_TRUE;

			if (error == 0)

				object = offset >> DNODE_SHIFT;

		}

		osi->os_obj_next = ++object;

		/*

		 * XXX We should check for an i/o error here and return

		 * up to our caller.  Actually we should pre-read it in

		 * dmu_tx_assign(), but there is currently no mechanism

		 * to do so.

		 */

		(void) dnode_hold_impl(os->os, object, DNODE_MUST_BE_FREE,

		    FTAG, &dn);

		if (dn)

			break;

		if (dmu_object_next(os, &object, B_TRUE, 0) == 0)

			osi->os_obj_next = object - 1;

	}

	dnode_allocate(dn, ot, blocksize, 0, bonustype, bonuslen, tx);

	dnode_rele(dn, FTAG);

	mutex_exit(&osi->os_obj_lock);

	dmu_tx_add_new_object(tx, os, object);

	return (object);

}

int

dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot,

    int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx)

{

	dnode_t *dn;

	int err;

	if (object == DMU_META_DNODE_OBJECT && !dmu_tx_private_ok(tx))

		return (EBADF);

	err = dnode_hold_impl(os->os, object, DNODE_MUST_BE_FREE, FTAG, &dn);

	if (err)

		return (err);

	dnode_allocate(dn, ot, blocksize, 0, bonustype, bonuslen, tx);

	dnode_rele(dn, FTAG);

	dmu_tx_add_new_object(tx, os, object);

	return (0);

}

int

dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot,

    int blocksize, dmu_object_type_t bonustype, int bonuslen)

{

	dnode_t *dn;

	dmu_tx_t *tx;

	int nblkptr;

	int err;

	if (object == DMU_META_DNODE_OBJECT)

		return (EBADF);

	err = dnode_hold_impl(os->os, object, DNODE_MUST_BE_ALLOCATED,

	    FTAG, &dn);

	if (err)

		return (err);

	if (dn->dn_type == ot && dn->dn_datablksz == blocksize &&

	    dn->dn_bonustype == bonustype && dn->dn_bonuslen == bonuslen) {

		/* nothing is changing, this is a noop */

		dnode_rele(dn, FTAG);

		return (0);

	}

	nblkptr = 1 + ((DN_MAX_BONUSLEN - bonuslen) >> SPA_BLKPTRSHIFT);

	/*

	 * If we are losing blkptrs or changing the block size this must

	 * be a new file instance.   We must clear out the previous file

	 * contents before we can change this type of metadata in the dnode.

	 */

	dnode_reallocate(dn, ot, blocksize, bonustype, bonuslen, tx);

	dmu_tx_commit(tx);

	dnode_rele(dn, FTAG);

}

int

dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx)

{

	dnode_t *dn;

	int err;

	ASSERT(object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx));

	err = dnode_hold_impl(os->os, object, DNODE_MUST_BE_ALLOCATED,

	    FTAG, &dn);

	if (err)

		return (err);

	ASSERT(dn->dn_type != DMU_OT_NONE);

	dnode_free_range(dn, 0, DMU_OBJECT_END, tx);

	dnode_free(dn, tx);

	dnode_rele(dn, FTAG);

	return (0);

}

int

dmu_object_next(objset_t *os, uint64_t *objectp, boolean_t hole, uint64_t txg)

{

	uint64_t offset = (*objectp + 1) << DNODE_SHIFT;

	int error;

	error = dnode_next_offset(os->os->os_meta_dnode,

	    (hole ? DNODE_FIND_HOLE : 0), &offset, 0, DNODES_PER_BLOCK, txg);

	*objectp = offset >> DNODE_SHIFT;

	return (error);

}