dsl_synctask.c revision f9af39bacaaa0f9dda3b75ff6858b9f3988a39af
/*
* 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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
*/
#include <sys/dmu.h>
#include <sys/dmu_tx.h>
#include <sys/dsl_pool.h>
#include <sys/dsl_dir.h>
#include <sys/dsl_synctask.h>
#include <sys/metaslab.h>
#define DST_AVG_BLKSHIFT 14
/* ARGSUSED */
static int
dsl_null_checkfunc(void *arg1, void *arg2, dmu_tx_t *tx)
{
return (0);
}
dsl_sync_task_group_t *
dsl_sync_task_group_create(dsl_pool_t *dp)
{
dsl_sync_task_group_t *dstg;
dstg = kmem_zalloc(sizeof (dsl_sync_task_group_t), KM_SLEEP);
list_create(&dstg->dstg_tasks, sizeof (dsl_sync_task_t),
offsetof(dsl_sync_task_t, dst_node));
dstg->dstg_pool = dp;
return (dstg);
}
void
dsl_sync_task_create(dsl_sync_task_group_t *dstg,
dsl_checkfunc_t *checkfunc, dsl_syncfunc_t *syncfunc,
void *arg1, void *arg2, int blocks_modified)
{
dsl_sync_task_t *dst;
if (checkfunc == NULL)
checkfunc = dsl_null_checkfunc;
dst = kmem_zalloc(sizeof (dsl_sync_task_t), KM_SLEEP);
dst->dst_checkfunc = checkfunc;
dst->dst_syncfunc = syncfunc;
dst->dst_arg1 = arg1;
dst->dst_arg2 = arg2;
list_insert_tail(&dstg->dstg_tasks, dst);
dstg->dstg_space += blocks_modified << DST_AVG_BLKSHIFT;
}
int
dsl_sync_task_group_wait(dsl_sync_task_group_t *dstg)
{
dmu_tx_t *tx;
uint64_t txg;
dsl_sync_task_t *dst;
top:
tx = dmu_tx_create_dd(dstg->dstg_pool->dp_mos_dir);
VERIFY(0 == dmu_tx_assign(tx, TXG_WAIT));
txg = dmu_tx_get_txg(tx);
/* Do a preliminary error check. */
dstg->dstg_err = 0;
rw_enter(&dstg->dstg_pool->dp_config_rwlock, RW_READER);
for (dst = list_head(&dstg->dstg_tasks); dst;
dst = list_next(&dstg->dstg_tasks, dst)) {
#ifdef ZFS_DEBUG
/*
* Only check half the time, otherwise, the sync-context
* check will almost never fail.
*/
if (spa_get_random(2) == 0)
continue;
#endif
dst->dst_err =
dst->dst_checkfunc(dst->dst_arg1, dst->dst_arg2, tx);
if (dst->dst_err)
dstg->dstg_err = dst->dst_err;
}
rw_exit(&dstg->dstg_pool->dp_config_rwlock);
if (dstg->dstg_err) {
dmu_tx_commit(tx);
return (dstg->dstg_err);
}
/*
* We don't generally have many sync tasks, so pay the price of
* add_tail to get the tasks executed in the right order.
*/
VERIFY(0 == txg_list_add_tail(&dstg->dstg_pool->dp_sync_tasks,
dstg, txg));
dmu_tx_commit(tx);
txg_wait_synced(dstg->dstg_pool, txg);
if (dstg->dstg_err == EAGAIN) {
txg_wait_synced(dstg->dstg_pool, txg + TXG_DEFER_SIZE);
goto top;
}
return (dstg->dstg_err);
}
void
dsl_sync_task_group_nowait(dsl_sync_task_group_t *dstg, dmu_tx_t *tx)
{
uint64_t txg;
dstg->dstg_nowaiter = B_TRUE;
txg = dmu_tx_get_txg(tx);
/*
* We don't generally have many sync tasks, so pay the price of
* add_tail to get the tasks executed in the right order.
*/
VERIFY(0 == txg_list_add_tail(&dstg->dstg_pool->dp_sync_tasks,
dstg, txg));
}
void
dsl_sync_task_group_destroy(dsl_sync_task_group_t *dstg)
{
dsl_sync_task_t *dst;
while (dst = list_head(&dstg->dstg_tasks)) {
list_remove(&dstg->dstg_tasks, dst);
kmem_free(dst, sizeof (dsl_sync_task_t));
}
kmem_free(dstg, sizeof (dsl_sync_task_group_t));
}
void
dsl_sync_task_group_sync(dsl_sync_task_group_t *dstg, dmu_tx_t *tx)
{
dsl_sync_task_t *dst;
dsl_pool_t *dp = dstg->dstg_pool;
uint64_t quota, used;
ASSERT3U(dstg->dstg_err, ==, 0);
/*
* Check for sufficient space. We just check against what's
* on-disk; we don't want any in-flight accounting to get in our
* way, because open context may have already used up various
* in-core limits (arc_tempreserve, dsl_pool_tempreserve).
*/
quota = dsl_pool_adjustedsize(dp, B_FALSE) -
metaslab_class_get_deferred(spa_normal_class(dp->dp_spa));
used = dp->dp_root_dir->dd_phys->dd_used_bytes;
/* MOS space is triple-dittoed, so we multiply by 3. */
if (dstg->dstg_space > 0 && used + dstg->dstg_space * 3 > quota) {
dstg->dstg_err = ENOSPC;
return;
}
/*
* Check for errors by calling checkfuncs.
*/
rw_enter(&dp->dp_config_rwlock, RW_WRITER);
for (dst = list_head(&dstg->dstg_tasks); dst;
dst = list_next(&dstg->dstg_tasks, dst)) {
dst->dst_err =
dst->dst_checkfunc(dst->dst_arg1, dst->dst_arg2, tx);
if (dst->dst_err)
dstg->dstg_err = dst->dst_err;
}
if (dstg->dstg_err == 0) {
/*
* Execute sync tasks.
*/
for (dst = list_head(&dstg->dstg_tasks); dst;
dst = list_next(&dstg->dstg_tasks, dst)) {
dst->dst_syncfunc(dst->dst_arg1, dst->dst_arg2, tx);
}
}
rw_exit(&dp->dp_config_rwlock);
if (dstg->dstg_nowaiter)
dsl_sync_task_group_destroy(dstg);
}
int
dsl_sync_task_do(dsl_pool_t *dp,
dsl_checkfunc_t *checkfunc, dsl_syncfunc_t *syncfunc,
void *arg1, void *arg2, int blocks_modified)
{
dsl_sync_task_group_t *dstg;
int err;
ASSERT(spa_writeable(dp->dp_spa));
dstg = dsl_sync_task_group_create(dp);
dsl_sync_task_create(dstg, checkfunc, syncfunc,
arg1, arg2, blocks_modified);
err = dsl_sync_task_group_wait(dstg);
dsl_sync_task_group_destroy(dstg);
return (err);
}
void
dsl_sync_task_do_nowait(dsl_pool_t *dp,
dsl_checkfunc_t *checkfunc, dsl_syncfunc_t *syncfunc,
void *arg1, void *arg2, int blocks_modified, dmu_tx_t *tx)
{
dsl_sync_task_group_t *dstg;
if (!spa_writeable(dp->dp_spa))
return;
dstg = dsl_sync_task_group_create(dp);
dsl_sync_task_create(dstg, checkfunc, syncfunc,
arg1, arg2, blocks_modified);
dsl_sync_task_group_nowait(dstg, tx);
}