1 files changed, 38 insertions, 23 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
index 21100225abf7..b0818ce274d4 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_synctask.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_synctask.c
@@ -19,18 +19,15 @@
  * CDDL HEADER END
  */
 /*
- * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
- * Use is subject to license terms.
+ * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  */
 
-#pragma ident	"%Z%%M%	%I%	%E% SMI"
-
 #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/cred.h>
+#include <sys/metaslab.h>
 
 #define	DST_AVG_BLKSHIFT 14
 
@@ -50,7 +47,6 @@ dsl_sync_task_group_create(dsl_pool_t *dp)
 	list_create(&dstg->dstg_tasks, sizeof (dsl_sync_task_t),
 	    offsetof(dsl_sync_task_t, dst_node));
 	dstg->dstg_pool = dp;
-	dstg->dstg_cr = CRED();
 
 	return (dstg);
 }
@@ -112,14 +108,21 @@ top:
 		return (dstg->dstg_err);
 	}
 
-	VERIFY(0 == txg_list_add(&dstg->dstg_pool->dp_sync_tasks, dstg, txg));
+	/*
+	 * We don't generally have many sync tasks, so pay the price of
+	 * add_tail to get the tasks executed in the right order.
+	 */
+	VERIFY(0 == txg_list_add_tail(&dstg->dstg_pool->dp_sync_tasks,
+	    dstg, txg));
 
 	dmu_tx_commit(tx);
 
 	txg_wait_synced(dstg->dstg_pool, txg);
 
-	if (dstg->dstg_err == EAGAIN)
+	if (dstg->dstg_err == EAGAIN) {
+		txg_wait_synced(dstg->dstg_pool, txg + TXG_DEFER_SIZE);
 		goto top;
+	}
 
 	return (dstg->dstg_err);
 }
@@ -131,7 +134,12 @@ dsl_sync_task_group_nowait(dsl_sync_task_group_t *dstg, dmu_tx_t *tx)
 
 	dstg->dstg_nowaiter = B_TRUE;
 	txg = dmu_tx_get_txg(tx);
-	VERIFY(0 == txg_list_add(&dstg->dstg_pool->dp_sync_tasks, dstg, txg));
+	/*
+	 * We don't generally have many sync tasks, so pay the price of
+	 * add_tail to get the tasks executed in the right order.
+	 */
+	VERIFY(0 == txg_list_add_tail(&dstg->dstg_pool->dp_sync_tasks,
+	    dstg, txg));
 }
 
 void
@@ -150,25 +158,30 @@ void
 dsl_sync_task_group_sync(dsl_sync_task_group_t *dstg, dmu_tx_t *tx)
 {
 	dsl_sync_task_t *dst;
-	void *tr_cookie;
+	dsl_pool_t *dp = dstg->dstg_pool;
+	uint64_t quota, used;
 
 	ASSERT3U(dstg->dstg_err, ==, 0);
 
 	/*
-	 * Check for sufficient space.
+	 * 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).
 	 */
-	dstg->dstg_err = dsl_dir_tempreserve_space(dstg->dstg_pool->dp_mos_dir,
-	    dstg->dstg_space, dstg->dstg_space * 3, 0, 0, &tr_cookie, tx);
-	/* don't bother trying again */
-	if (dstg->dstg_err == ERESTART)
-		dstg->dstg_err = EAGAIN;
-	if (dstg->dstg_err)
+	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 (dstg->dstg_space > 0 && used + dstg->dstg_space * 3 > quota) {
+		dstg->dstg_err = ENOSPC;
 		return;
+	}
 
 	/*
 	 * Check for errors by calling checkfuncs.
 	 */
-	rw_enter(&dstg->dstg_pool->dp_config_rwlock, RW_WRITER);
+	rw_enter(&dp->dp_config_rwlock, RW_WRITER);
 	for (dst = list_head(&dstg->dstg_tasks); dst;
 	    dst = list_next(&dstg->dstg_tasks, dst)) {
 		dst->dst_err =
@@ -183,13 +196,10 @@ dsl_sync_task_group_sync(dsl_sync_task_group_t *dstg, dmu_tx_t *tx)
 		 */
 		for (dst = list_head(&dstg->dstg_tasks); dst;
 		    dst = list_next(&dstg->dstg_tasks, dst)) {
-			dst->dst_syncfunc(dst->dst_arg1, dst->dst_arg2,
-			    dstg->dstg_cr, tx);
+			dst->dst_syncfunc(dst->dst_arg1, dst->dst_arg2, tx);
 		}
 	}
-	rw_exit(&dstg->dstg_pool->dp_config_rwlock);
-
-	dsl_dir_tempreserve_clear(tr_cookie, tx);
+	rw_exit(&dp->dp_config_rwlock);
 
 	if (dstg->dstg_nowaiter)
 		dsl_sync_task_group_destroy(dstg);
@@ -203,6 +213,8 @@ dsl_sync_task_do(dsl_pool_t *dp,
 	dsl_sync_task_group_t *dstg;
 	int err;
 
+	ASSERT(spa_writeable(dp->dp_spa));
+
 	dstg = dsl_sync_task_group_create(dp);
 	dsl_sync_task_create(dstg, checkfunc, syncfunc,
 	    arg1, arg2, blocks_modified);
@@ -218,6 +230,9 @@ dsl_sync_task_do_nowait(dsl_pool_t *dp,
 {
 	dsl_sync_task_group_t *dstg;
 
+	if (!spa_writeable(dp->dp_spa))
+		return;
+
 	dstg = dsl_sync_task_group_create(dp);
 	dsl_sync_task_create(dstg, checkfunc, syncfunc,
 	    arg1, arg2, blocks_modified);