xref: /titanic_41/usr/src/uts/common/fs/zfs/dsl_synctask.c (revision 936b7af69172dce89b577831f79c0e18d15e854b)
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 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 #include <sys/dmu.h>
29 #include <sys/dmu_tx.h>
30 #include <sys/dsl_pool.h>
31 #include <sys/dsl_dir.h>
32 #include <sys/dsl_synctask.h>
33 #include <sys/cred.h>
34 
35 #define	DST_AVG_BLKSHIFT 14
36 
37 /* ARGSUSED */
38 static int
39 dsl_null_checkfunc(void *arg1, void *arg2, dmu_tx_t *tx)
40 {
41 	return (0);
42 }
43 
44 dsl_sync_task_group_t *
45 dsl_sync_task_group_create(dsl_pool_t *dp)
46 {
47 	dsl_sync_task_group_t *dstg;
48 
49 	dstg = kmem_zalloc(sizeof (dsl_sync_task_group_t), KM_SLEEP);
50 	list_create(&dstg->dstg_tasks, sizeof (dsl_sync_task_t),
51 	    offsetof(dsl_sync_task_t, dst_node));
52 	dstg->dstg_pool = dp;
53 	dstg->dstg_cr = CRED();
54 
55 	return (dstg);
56 }
57 
58 void
59 dsl_sync_task_create(dsl_sync_task_group_t *dstg,
60     dsl_checkfunc_t *checkfunc, dsl_syncfunc_t *syncfunc,
61     void *arg1, void *arg2, int blocks_modified)
62 {
63 	dsl_sync_task_t *dst;
64 
65 	if (checkfunc == NULL)
66 		checkfunc = dsl_null_checkfunc;
67 	dst = kmem_zalloc(sizeof (dsl_sync_task_t), KM_SLEEP);
68 	dst->dst_checkfunc = checkfunc;
69 	dst->dst_syncfunc = syncfunc;
70 	dst->dst_arg1 = arg1;
71 	dst->dst_arg2 = arg2;
72 	list_insert_tail(&dstg->dstg_tasks, dst);
73 
74 	dstg->dstg_space += blocks_modified << DST_AVG_BLKSHIFT;
75 }
76 
77 int
78 dsl_sync_task_group_wait(dsl_sync_task_group_t *dstg)
79 {
80 	dmu_tx_t *tx;
81 	uint64_t txg;
82 	dsl_sync_task_t *dst;
83 
84 top:
85 	tx = dmu_tx_create_dd(dstg->dstg_pool->dp_mos_dir);
86 	VERIFY(0 == dmu_tx_assign(tx, TXG_WAIT));
87 
88 	txg = dmu_tx_get_txg(tx);
89 
90 	/* Do a preliminary error check. */
91 	dstg->dstg_err = 0;
92 	rw_enter(&dstg->dstg_pool->dp_config_rwlock, RW_READER);
93 	for (dst = list_head(&dstg->dstg_tasks); dst;
94 	    dst = list_next(&dstg->dstg_tasks, dst)) {
95 #ifdef ZFS_DEBUG
96 		/*
97 		 * Only check half the time, otherwise, the sync-context
98 		 * check will almost never fail.
99 		 */
100 		if (spa_get_random(2) == 0)
101 			continue;
102 #endif
103 		dst->dst_err =
104 		    dst->dst_checkfunc(dst->dst_arg1, dst->dst_arg2, tx);
105 		if (dst->dst_err)
106 			dstg->dstg_err = dst->dst_err;
107 	}
108 	rw_exit(&dstg->dstg_pool->dp_config_rwlock);
109 
110 	if (dstg->dstg_err) {
111 		dmu_tx_commit(tx);
112 		return (dstg->dstg_err);
113 	}
114 
115 	VERIFY(0 == txg_list_add(&dstg->dstg_pool->dp_sync_tasks, dstg, txg));
116 
117 	dmu_tx_commit(tx);
118 
119 	txg_wait_synced(dstg->dstg_pool, txg);
120 
121 	if (dstg->dstg_err == EAGAIN)
122 		goto top;
123 
124 	return (dstg->dstg_err);
125 }
126 
127 void
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
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
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
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
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