zfs/module/zfs/dsl_synctask.c

231 lines
5.6 KiB
C

/*
* 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 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#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/cred.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;
dstg->dstg_cr = CRED();
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);
}
VERIFY(0 == txg_list_add(&dstg->dstg_pool->dp_sync_tasks, dstg, txg));
dmu_tx_commit(tx);
txg_wait_synced(dstg->dstg_pool, txg);
if (dstg->dstg_err == EAGAIN)
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);
VERIFY(0 == txg_list_add(&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;
void *tr_cookie;
ASSERT3U(dstg->dstg_err, ==, 0);
/*
* Check for sufficient space.
*/
dstg->dstg_err = dsl_dir_tempreserve_space(dstg->dstg_pool->dp_mos_dir,
dstg->dstg_space, dstg->dstg_space * 3, 0, 0, &tr_cookie, tx);
/* don't bother trying again */
if (dstg->dstg_err == ERESTART)
dstg->dstg_err = EAGAIN;
if (dstg->dstg_err)
return;
/*
* Check for errors by calling checkfuncs.
*/
rw_enter(&dstg->dstg_pool->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,
dstg->dstg_cr, tx);
}
}
rw_exit(&dstg->dstg_pool->dp_config_rwlock);
dsl_dir_tempreserve_clear(tr_cookie, tx);
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;
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;
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);
}
#if defined(_KERNEL) && defined(HAVE_SPL)
EXPORT_SYMBOL(dsl_sync_task_do);
EXPORT_SYMBOL(dsl_sync_task_do_nowait);
#endif