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4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2013 by Delphix. All rights reserved.
27 #include <sys/dmu_tx.h>
28 #include <sys/dsl_pool.h>
29 #include <sys/dsl_dir.h>
30 #include <sys/dsl_synctask.h>
31 #include <sys/metaslab.h>
33 #define DST_AVG_BLKSHIFT 14
37 dsl_null_checkfunc(void *arg
, dmu_tx_t
*tx
)
43 * Called from open context to perform a callback in syncing context. Waits
44 * for the operation to complete.
46 * The checkfunc will be called from open context as a preliminary check
47 * which can quickly fail. If it succeeds, it will be called again from
48 * syncing context. The checkfunc should generally be designed to work
49 * properly in either context, but if necessary it can check
50 * dmu_tx_is_syncing(tx).
52 * The synctask infrastructure enforces proper locking strategy with respect
53 * to the dp_config_rwlock -- the lock will always be held when the callbacks
54 * are called. It will be held for read during the open-context (preliminary)
55 * call to the checkfunc, and then held for write from syncing context during
56 * the calls to the check and sync funcs.
58 * A dataset or pool name can be passed as the first argument. Typically,
59 * the check func will hold, check the return value of the hold, and then
60 * release the dataset. The sync func will VERIFYO(hold()) the dataset.
61 * This is safe because no changes can be made between the check and sync funcs,
62 * and the sync func will only be called if the check func successfully opened
66 dsl_sync_task(const char *pool
, dsl_checkfunc_t
*checkfunc
,
67 dsl_syncfunc_t
*syncfunc
, void *arg
, int blocks_modified
)
72 dsl_sync_task_t dst
= { { { NULL
} } };
75 err
= spa_open(pool
, &spa
, FTAG
);
78 dp
= spa_get_dsl(spa
);
81 tx
= dmu_tx_create_dd(dp
->dp_mos_dir
);
82 VERIFY0(dmu_tx_assign(tx
, TXG_WAIT
));
85 dst
.dst_txg
= dmu_tx_get_txg(tx
);
86 dst
.dst_space
= blocks_modified
<< DST_AVG_BLKSHIFT
;
87 dst
.dst_checkfunc
= checkfunc
!= NULL
? checkfunc
: dsl_null_checkfunc
;
88 dst
.dst_syncfunc
= syncfunc
;
91 dst
.dst_nowaiter
= B_FALSE
;
93 dsl_pool_config_enter(dp
, FTAG
);
94 err
= dst
.dst_checkfunc(arg
, tx
);
95 dsl_pool_config_exit(dp
, FTAG
);
103 VERIFY(txg_list_add_tail(&dp
->dp_sync_tasks
, &dst
, dst
.dst_txg
));
107 txg_wait_synced(dp
, dst
.dst_txg
);
109 if (dst
.dst_error
== EAGAIN
) {
110 txg_wait_synced(dp
, dst
.dst_txg
+ TXG_DEFER_SIZE
);
114 spa_close(spa
, FTAG
);
115 return (dst
.dst_error
);
119 dsl_sync_task_nowait(dsl_pool_t
*dp
, dsl_syncfunc_t
*syncfunc
, void *arg
,
120 int blocks_modified
, dmu_tx_t
*tx
)
122 dsl_sync_task_t
*dst
= kmem_zalloc(sizeof (*dst
), KM_SLEEP
);
125 dst
->dst_txg
= dmu_tx_get_txg(tx
);
126 dst
->dst_space
= blocks_modified
<< DST_AVG_BLKSHIFT
;
127 dst
->dst_checkfunc
= dsl_null_checkfunc
;
128 dst
->dst_syncfunc
= syncfunc
;
131 dst
->dst_nowaiter
= B_TRUE
;
133 VERIFY(txg_list_add_tail(&dp
->dp_sync_tasks
, dst
, dst
->dst_txg
));
137 * Called in syncing context to execute the synctask.
140 dsl_sync_task_sync(dsl_sync_task_t
*dst
, dmu_tx_t
*tx
)
142 dsl_pool_t
*dp
= dst
->dst_pool
;
143 uint64_t quota
, used
;
145 ASSERT0(dst
->dst_error
);
148 * Check for sufficient space. We just check against what's
149 * on-disk; we don't want any in-flight accounting to get in our
150 * way, because open context may have already used up various
151 * in-core limits (arc_tempreserve, dsl_pool_tempreserve).
153 quota
= dsl_pool_adjustedsize(dp
, B_FALSE
) -
154 metaslab_class_get_deferred(spa_normal_class(dp
->dp_spa
));
155 used
= dsl_dir_phys(dp
->dp_root_dir
)->dd_used_bytes
;
156 /* MOS space is triple-dittoed, so we multiply by 3. */
157 if (dst
->dst_space
> 0 && used
+ dst
->dst_space
* 3 > quota
) {
158 dst
->dst_error
= SET_ERROR(ENOSPC
);
159 if (dst
->dst_nowaiter
)
160 kmem_free(dst
, sizeof (*dst
));
165 * Check for errors by calling checkfunc.
167 rrw_enter(&dp
->dp_config_rwlock
, RW_WRITER
, FTAG
);
168 dst
->dst_error
= dst
->dst_checkfunc(dst
->dst_arg
, tx
);
169 if (dst
->dst_error
== 0)
170 dst
->dst_syncfunc(dst
->dst_arg
, tx
);
171 rrw_exit(&dp
->dp_config_rwlock
, FTAG
);
172 if (dst
->dst_nowaiter
)
173 kmem_free(dst
, sizeof (*dst
));
176 #if defined(_KERNEL) && defined(HAVE_SPL)
177 EXPORT_SYMBOL(dsl_sync_task
);
178 EXPORT_SYMBOL(dsl_sync_task_nowait
);