zfs/lib/libzpool/dsl_synctask.c

   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 }