Finally... Import the latest open-source ZFS version - (SPA) 28.

Few new things available from now on:

- Data deduplication.
- Triple parity RAIDZ (RAIDZ3).
- zfs diff.
- zpool split.
- Snapshot holds.
- zpool import -F. Allows to rewind corrupted pool to earlier
  transaction group.
- Possibility to import pool in read-only mode.

MFC after:	1 month

1 files changed, 5 insertions, 6 deletions

diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/space_map.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/space_map.c
index d025141..1ce7b2a 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/space_map.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/space_map.c
@@ -258,8 +258,10 @@ space_map_load_wait(space_map_t *sm)
 {
 	ASSERT(MUTEX_HELD(sm->sm_lock));
 
-	while (sm->sm_loading)
+	while (sm->sm_loading) {
+		ASSERT(!sm->sm_loaded);
 		cv_wait(&sm->sm_load_cv, sm->sm_lock);
+	}
 }
 
 /*
@@ -276,11 +278,8 @@ space_map_load(space_map_t *sm, space_map_ops_t *ops, uint8_t maptype,
 	int error = 0;
 
 	ASSERT(MUTEX_HELD(sm->sm_lock));
-
-	space_map_load_wait(sm);
-
-	if (sm->sm_loaded)
-		return (0);
+	ASSERT(!sm->sm_loaded);
+	ASSERT(!sm->sm_loading);
 
 	sm->sm_loading = B_TRUE;
 	end = smo->smo_objsize;