/*

 * 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 2006 Sun Microsystems, Inc.  All rights reserved.

 * Use is subject to license terms.

 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

#include <sys/dsl_pool.h>

#include <sys/dsl_dataset.h>

#include <sys/dsl_dir.h>

#include <sys/dmu_tx.h>

#include <sys/dmu_objset.h>

#include <sys/arc.h>

#include <sys/zap.h>

#include <sys/zfs_context.h>

#include <sys/fs/zfs.h>

/* internal reserved dir name */

#define	MOS_DIR_NAME "$MOS"

static int

dsl_pool_open_mos_dir(dsl_pool_t *dp, dsl_dir_t **ddp)

{

	uint64_t obj;

	int err;

	err = zap_lookup(dp->dp_meta_objset,

	    dp->dp_root_dir->dd_phys->dd_child_dir_zapobj,

	    MOS_DIR_NAME, sizeof (obj), 1, &obj);

	if (err)

		return (err);

	return (dsl_dir_open_obj(dp, obj, MOS_DIR_NAME, dp, ddp));

}

static dsl_pool_t *

dsl_pool_open_impl(spa_t *spa, uint64_t txg)

{

	dsl_pool_t *dp;

	blkptr_t *bp = spa_get_rootblkptr(spa);

	dp = kmem_zalloc(sizeof (dsl_pool_t), KM_SLEEP);

	dp->dp_spa = spa;

	dp->dp_meta_rootbp = *bp;

	txg_init(dp, txg);

	txg_list_create(&dp->dp_dirty_datasets,

	    offsetof(dsl_dataset_t, ds_dirty_link));

	txg_list_create(&dp->dp_dirty_dirs,

	    offsetof(dsl_dir_t, dd_dirty_link));

	list_create(&dp->dp_synced_objsets, sizeof (dsl_dataset_t),

	    offsetof(dsl_dataset_t, ds_synced_link));

	return (dp);

}

int

dsl_pool_open(spa_t *spa, uint64_t txg, dsl_pool_t **dpp)

{

	int err;

	dsl_pool_t *dp = dsl_pool_open_impl(spa, txg);

	objset_impl_t *osi;

	rw_enter(&dp->dp_config_rwlock, RW_READER);

	err = dmu_objset_open_impl(spa, NULL, &dp->dp_meta_rootbp, &osi);

	if (err)

		goto out;

	dp->dp_meta_objset = &osi->os;

	err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,

	    DMU_POOL_ROOT_DATASET, sizeof (uint64_t), 1,

	    &dp->dp_root_dir_obj);

	if (err)

		goto out;

	err = dsl_dir_open_obj(dp, dp->dp_root_dir_obj,

	    NULL, dp, &dp->dp_root_dir);

	if (err)

		goto out;

	err = dsl_pool_open_mos_dir(dp, &dp->dp_mos_dir);

	if (err)

		goto out;

out:

	rw_exit(&dp->dp_config_rwlock);

	if (err)

		dsl_pool_close(dp);

	else

		*dpp = dp;

	return (err);

}

void

dsl_pool_close(dsl_pool_t *dp)

{

	/* drop our reference from dsl_pool_open() */

	if (dp->dp_mos_dir)

		dsl_dir_close(dp->dp_mos_dir, dp);

	if (dp->dp_root_dir)

		dsl_dir_close(dp->dp_root_dir, dp);

	/* undo the dmu_objset_open_impl(mos) from dsl_pool_open() */

	if (dp->dp_meta_objset)

		dmu_objset_evict(NULL, dp->dp_meta_objset->os);

	txg_list_destroy(&dp->dp_dirty_datasets);

	txg_list_destroy(&dp->dp_dirty_dirs);

	list_destroy(&dp->dp_synced_objsets);

	arc_flush();

	txg_fini(dp);

	kmem_free(dp, sizeof (dsl_pool_t));

}

dsl_pool_t *

dsl_pool_create(spa_t *spa, uint64_t txg)

{

	int err;

	dsl_pool_t *dp = dsl_pool_open_impl(spa, txg);

	dmu_tx_t *tx = dmu_tx_create_assigned(dp, txg);

	dp->dp_meta_objset = &dmu_objset_create_impl(spa,

	    NULL, DMU_OST_META, tx)->os;

	/* create the pool directory */

	err = zap_create_claim(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,

	    DMU_OT_OBJECT_DIRECTORY, DMU_OT_NONE, 0, tx);

	ASSERT3U(err, ==, 0);

	/* create and open the root dir */

	dsl_dataset_create_root(dp, &dp->dp_root_dir_obj, tx);

	VERIFY(0 == dsl_dir_open_obj(dp, dp->dp_root_dir_obj,

	    NULL, dp, &dp->dp_root_dir));

	/* create and open the meta-objset dir */

	VERIFY(0 == dsl_dir_create_sync(dp->dp_root_dir, MOS_DIR_NAME, tx));

	ASSERT3U(err, ==, 0);

	VERIFY(0 == dsl_pool_open_mos_dir(dp, &dp->dp_mos_dir));

	dmu_tx_commit(tx);

	return (dp);

}

void

dsl_pool_sync(dsl_pool_t *dp, uint64_t txg)

{

	dmu_tx_t *tx;

	objset_impl_t *mosi = dp->dp_meta_objset->os;

	tx = dmu_tx_create_assigned(dp, txg);

	do {

		dsl_dir_t *dd;

		dsl_dataset_t *ds;

		while (ds = txg_list_remove(&dp->dp_dirty_datasets, txg)) {

			if (!list_link_active(&ds->ds_synced_link))

				list_insert_tail(&dp->dp_synced_objsets, ds);

			dsl_dataset_sync(ds, tx);

		}

		while (dd = txg_list_remove(&dp->dp_dirty_dirs, txg))

			dsl_dir_sync(dd, tx);

		/*

		 * We need to loop since dsl_dir_sync() could create a

		 * new (dirty) objset.

		 * XXX - isn't this taken care of by the spa's sync to

		 * convergence loop?

		 */

	} while (!txg_list_empty(&dp->dp_dirty_datasets, txg));

	if (list_head(&mosi->os_dirty_dnodes[txg & TXG_MASK]) != NULL ||

	    list_head(&mosi->os_free_dnodes[txg & TXG_MASK]) != NULL) {

		dmu_objset_sync(mosi, tx);

		dprintf_bp(&dp->dp_meta_rootbp, "meta objset rootbp is %s", "");

		spa_set_rootblkptr(dp->dp_spa, &dp->dp_meta_rootbp);

	}

	dmu_tx_commit(tx);

}

void

dsl_pool_zil_clean(dsl_pool_t *dp)

{

	dsl_dataset_t *ds;

	while (ds = list_head(&dp->dp_synced_objsets)) {

		list_remove(&dp->dp_synced_objsets, ds);

		ASSERT(ds->ds_user_ptr != NULL);

		zil_clean(((objset_impl_t *)ds->ds_user_ptr)->os_zil);

	}

}

int

dsl_pool_sync_context(dsl_pool_t *dp)

{

	/*

	 * Yeah, this is cheesy.  But the SPA needs some way to let

	 * the sync threads invoke spa_open() and spa_close() while

	 * it holds the namespace lock.  I'm certainly open to better

	 * ideas for how to determine whether the current thread is

	 * operating on behalf of spa_sync().  This works for now.

	 */

	return (curthread == dp->dp_tx.tx_sync_thread ||

	    BP_IS_HOLE(&dp->dp_meta_rootbp));

}

uint64_t

dsl_pool_adjustedsize(dsl_pool_t *dp, boolean_t netfree)

{

	uint64_t space, resv;

	/*

	 * Reserve about 1% (1/128), or at least 16MB, for allocation

	 * efficiency.

	 * XXX The intent log is not accounted for, so it must fit

	 * within this slop.

	 *

	 * If we're trying to assess whether it's OK to do a free,

	 * cut the reservation in half to allow forward progress

	 * (e.g. make it possible to rm(1) files from a full pool).

	 */

	space = spa_get_space(dp->dp_spa);

	resv = MAX(space >> 7, SPA_MINDEVSIZE >> 2);

	if (netfree)

		resv >>= 1;

	return (space - resv);

}