diff options
Diffstat (limited to 'sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_synctask.c')
-rw-r--r-- | sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_synctask.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_synctask.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_synctask.c new file mode 100644 index 0000000..58f7d37 --- /dev/null +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_synctask.c @@ -0,0 +1,174 @@ +/* + * 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. + * Copyright (c) 2013 by Delphix. 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 *arg, dmu_tx_t *tx) +{ + return (0); +} + +/* + * Called from open context to perform a callback in syncing context. Waits + * for the operation to complete. + * + * The checkfunc will be called from open context as a preliminary check + * which can quickly fail. If it succeeds, it will be called again from + * syncing context. The checkfunc should generally be designed to work + * properly in either context, but if necessary it can check + * dmu_tx_is_syncing(tx). + * + * The synctask infrastructure enforces proper locking strategy with respect + * to the dp_config_rwlock -- the lock will always be held when the callbacks + * are called. It will be held for read during the open-context (preliminary) + * call to the checkfunc, and then held for write from syncing context during + * the calls to the check and sync funcs. + * + * A dataset or pool name can be passed as the first argument. Typically, + * the check func will hold, check the return value of the hold, and then + * release the dataset. The sync func will VERIFYO(hold()) the dataset. + * This is safe because no changes can be made between the check and sync funcs, + * and the sync func will only be called if the check func successfully opened + * the dataset. + */ +int +dsl_sync_task(const char *pool, dsl_checkfunc_t *checkfunc, + dsl_syncfunc_t *syncfunc, void *arg, int blocks_modified) +{ + spa_t *spa; + dmu_tx_t *tx; + int err; + dsl_sync_task_t dst = { 0 }; + dsl_pool_t *dp; + + err = spa_open(pool, &spa, FTAG); + if (err != 0) + return (err); + dp = spa_get_dsl(spa); + +top: + tx = dmu_tx_create_dd(dp->dp_mos_dir); + VERIFY0(dmu_tx_assign(tx, TXG_WAIT)); + + dst.dst_pool = dp; + dst.dst_txg = dmu_tx_get_txg(tx); + dst.dst_space = blocks_modified << DST_AVG_BLKSHIFT; + dst.dst_checkfunc = checkfunc != NULL ? checkfunc : dsl_null_checkfunc; + dst.dst_syncfunc = syncfunc; + dst.dst_arg = arg; + dst.dst_error = 0; + dst.dst_nowaiter = B_FALSE; + + dsl_pool_config_enter(dp, FTAG); + err = dst.dst_checkfunc(arg, tx); + dsl_pool_config_exit(dp, FTAG); + + if (err != 0) { + dmu_tx_commit(tx); + spa_close(spa, FTAG); + return (err); + } + + VERIFY(txg_list_add_tail(&dp->dp_sync_tasks, &dst, dst.dst_txg)); + + dmu_tx_commit(tx); + + txg_wait_synced(dp, dst.dst_txg); + + if (dst.dst_error == EAGAIN) { + txg_wait_synced(dp, dst.dst_txg + TXG_DEFER_SIZE); + goto top; + } + + spa_close(spa, FTAG); + return (dst.dst_error); +} + +void +dsl_sync_task_nowait(dsl_pool_t *dp, dsl_syncfunc_t *syncfunc, void *arg, + int blocks_modified, dmu_tx_t *tx) +{ + dsl_sync_task_t *dst = kmem_zalloc(sizeof (*dst), KM_SLEEP); + + dst->dst_pool = dp; + dst->dst_txg = dmu_tx_get_txg(tx); + dst->dst_space = blocks_modified << DST_AVG_BLKSHIFT; + dst->dst_checkfunc = dsl_null_checkfunc; + dst->dst_syncfunc = syncfunc; + dst->dst_arg = arg; + dst->dst_error = 0; + dst->dst_nowaiter = B_TRUE; + + VERIFY(txg_list_add_tail(&dp->dp_sync_tasks, dst, dst->dst_txg)); +} + +/* + * Called in syncing context to execute the synctask. + */ +void +dsl_sync_task_sync(dsl_sync_task_t *dst, dmu_tx_t *tx) +{ + dsl_pool_t *dp = dst->dst_pool; + uint64_t quota, used; + + ASSERT0(dst->dst_error); + + /* + * 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 (dst->dst_space > 0 && used + dst->dst_space * 3 > quota) { + dst->dst_error = SET_ERROR(ENOSPC); + if (dst->dst_nowaiter) + kmem_free(dst, sizeof (*dst)); + return; + } + + /* + * Check for errors by calling checkfunc. + */ + rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG); + dst->dst_error = dst->dst_checkfunc(dst->dst_arg, tx); + if (dst->dst_error == 0) + dst->dst_syncfunc(dst->dst_arg, tx); + rrw_exit(&dp->dp_config_rwlock, FTAG); + if (dst->dst_nowaiter) + kmem_free(dst, sizeof (*dst)); +} |