1 /*
2 * CDDL HEADER START
3 *
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.
7 *
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.
12 *
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]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26 #include <sys/dmu.h>
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/cred.h>
32
33 #define DST_AVG_BLKSHIFT 14
34
35 /* ARGSUSED */
36 static int
dsl_null_checkfunc(void * arg1,void * arg2,dmu_tx_t * tx)37 dsl_null_checkfunc(void *arg1, void *arg2, dmu_tx_t *tx)
38 {
39 return (0);
40 }
41
42 dsl_sync_task_group_t *
dsl_sync_task_group_create(dsl_pool_t * dp)43 dsl_sync_task_group_create(dsl_pool_t *dp)
44 {
45 dsl_sync_task_group_t *dstg;
46
47 dstg = kmem_zalloc(sizeof (dsl_sync_task_group_t), KM_SLEEP);
48 list_create(&dstg->dstg_tasks, sizeof (dsl_sync_task_t),
49 offsetof(dsl_sync_task_t, dst_node));
50 dstg->dstg_pool = dp;
51 dstg->dstg_cr = CRED();
52
53 return (dstg);
54 }
55
56 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)57 dsl_sync_task_create(dsl_sync_task_group_t *dstg,
58 dsl_checkfunc_t *checkfunc, dsl_syncfunc_t *syncfunc,
59 void *arg1, void *arg2, int blocks_modified)
60 {
61 dsl_sync_task_t *dst;
62
63 if (checkfunc == NULL)
64 checkfunc = dsl_null_checkfunc;
65 dst = kmem_zalloc(sizeof (dsl_sync_task_t), KM_SLEEP);
66 dst->dst_checkfunc = checkfunc;
67 dst->dst_syncfunc = syncfunc;
68 dst->dst_arg1 = arg1;
69 dst->dst_arg2 = arg2;
70 list_insert_tail(&dstg->dstg_tasks, dst);
71
72 dstg->dstg_space += blocks_modified << DST_AVG_BLKSHIFT;
73 }
74
75 int
dsl_sync_task_group_wait(dsl_sync_task_group_t * dstg)76 dsl_sync_task_group_wait(dsl_sync_task_group_t *dstg)
77 {
78 dmu_tx_t *tx;
79 uint64_t txg;
80 dsl_sync_task_t *dst;
81
82 top:
83 tx = dmu_tx_create_dd(dstg->dstg_pool->dp_mos_dir);
84 VERIFY(0 == dmu_tx_assign(tx, TXG_WAIT));
85
86 txg = dmu_tx_get_txg(tx);
87
88 /* Do a preliminary error check. */
89 dstg->dstg_err = 0;
90 rw_enter(&dstg->dstg_pool->dp_config_rwlock, RW_READER);
91 for (dst = list_head(&dstg->dstg_tasks); dst;
92 dst = list_next(&dstg->dstg_tasks, dst)) {
93 #ifdef ZFS_DEBUG
94 /*
95 * Only check half the time, otherwise, the sync-context
96 * check will almost never fail.
97 */
98 if (spa_get_random(2) == 0)
99 continue;
100 #endif
101 dst->dst_err =
102 dst->dst_checkfunc(dst->dst_arg1, dst->dst_arg2, tx);
103 if (dst->dst_err)
104 dstg->dstg_err = dst->dst_err;
105 }
106 rw_exit(&dstg->dstg_pool->dp_config_rwlock);
107
108 if (dstg->dstg_err) {
109 dmu_tx_commit(tx);
110 return (dstg->dstg_err);
111 }
112
113 VERIFY(0 == txg_list_add(&dstg->dstg_pool->dp_sync_tasks, dstg, txg));
114
115 dmu_tx_commit(tx);
116
117 txg_wait_synced(dstg->dstg_pool, txg);
118
119 if (dstg->dstg_err == EAGAIN) {
120 txg_wait_synced(dstg->dstg_pool, txg + TXG_DEFER_SIZE);
121 goto top;
122 }
123
124 return (dstg->dstg_err);
125 }
126
127 void
dsl_sync_task_group_nowait(dsl_sync_task_group_t * dstg,dmu_tx_t * tx)128 dsl_sync_task_group_nowait(dsl_sync_task_group_t *dstg, dmu_tx_t *tx)
129 {
130 uint64_t txg;
131
132 dstg->dstg_nowaiter = B_TRUE;
133 txg = dmu_tx_get_txg(tx);
134 VERIFY(0 == txg_list_add(&dstg->dstg_pool->dp_sync_tasks, dstg, txg));
135 }
136
137 void
dsl_sync_task_group_destroy(dsl_sync_task_group_t * dstg)138 dsl_sync_task_group_destroy(dsl_sync_task_group_t *dstg)
139 {
140 dsl_sync_task_t *dst;
141
142 while (dst = list_head(&dstg->dstg_tasks)) {
143 list_remove(&dstg->dstg_tasks, dst);
144 kmem_free(dst, sizeof (dsl_sync_task_t));
145 }
146 kmem_free(dstg, sizeof (dsl_sync_task_group_t));
147 }
148
149 void
dsl_sync_task_group_sync(dsl_sync_task_group_t * dstg,dmu_tx_t * tx)150 dsl_sync_task_group_sync(dsl_sync_task_group_t *dstg, dmu_tx_t *tx)
151 {
152 dsl_sync_task_t *dst;
153 void *tr_cookie;
154
155 ASSERT3U(dstg->dstg_err, ==, 0);
156
157 /*
158 * Check for sufficient space.
159 */
160 dstg->dstg_err = dsl_dir_tempreserve_space(dstg->dstg_pool->dp_mos_dir,
161 dstg->dstg_space, dstg->dstg_space * 3, 0, 0, &tr_cookie, tx);
162 /* don't bother trying again */
163 if (dstg->dstg_err == ERESTART)
164 dstg->dstg_err = EAGAIN;
165 if (dstg->dstg_err)
166 return;
167
168 /*
169 * Check for errors by calling checkfuncs.
170 */
171 rw_enter(&dstg->dstg_pool->dp_config_rwlock, RW_WRITER);
172 for (dst = list_head(&dstg->dstg_tasks); dst;
173 dst = list_next(&dstg->dstg_tasks, dst)) {
174 dst->dst_err =
175 dst->dst_checkfunc(dst->dst_arg1, dst->dst_arg2, tx);
176 if (dst->dst_err)
177 dstg->dstg_err = dst->dst_err;
178 }
179
180 if (dstg->dstg_err == 0) {
181 /*
182 * Execute sync tasks.
183 */
184 for (dst = list_head(&dstg->dstg_tasks); dst;
185 dst = list_next(&dstg->dstg_tasks, dst)) {
186 dst->dst_syncfunc(dst->dst_arg1, dst->dst_arg2,
187 dstg->dstg_cr, tx);
188 }
189 }
190 rw_exit(&dstg->dstg_pool->dp_config_rwlock);
191
192 dsl_dir_tempreserve_clear(tr_cookie, tx);
193
194 if (dstg->dstg_nowaiter)
195 dsl_sync_task_group_destroy(dstg);
196 }
197
198 int
dsl_sync_task_do(dsl_pool_t * dp,dsl_checkfunc_t * checkfunc,dsl_syncfunc_t * syncfunc,void * arg1,void * arg2,int blocks_modified)199 dsl_sync_task_do(dsl_pool_t *dp,
200 dsl_checkfunc_t *checkfunc, dsl_syncfunc_t *syncfunc,
201 void *arg1, void *arg2, int blocks_modified)
202 {
203 dsl_sync_task_group_t *dstg;
204 int err;
205
206 dstg = dsl_sync_task_group_create(dp);
207 dsl_sync_task_create(dstg, checkfunc, syncfunc,
208 arg1, arg2, blocks_modified);
209 err = dsl_sync_task_group_wait(dstg);
210 dsl_sync_task_group_destroy(dstg);
211 return (err);
212 }
213
214 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)215 dsl_sync_task_do_nowait(dsl_pool_t *dp,
216 dsl_checkfunc_t *checkfunc, dsl_syncfunc_t *syncfunc,
217 void *arg1, void *arg2, int blocks_modified, dmu_tx_t *tx)
218 {
219 dsl_sync_task_group_t *dstg;
220
221 dstg = dsl_sync_task_group_create(dp);
222 dsl_sync_task_create(dstg, checkfunc, syncfunc,
223 arg1, arg2, blocks_modified);
224 dsl_sync_task_group_nowait(dstg, tx);
225 }
226