Import OpenSolaris revision 7837:001de5627df3

It includes the following changes:
- parallel reads in traversal code (Bug ID 6333409)
- faster traversal for zfs send (Bug ID 6418042)
- traversal code cleanup (Bug ID 6725675)
- fix for two scrub related bugs (Bug ID 6729696, 6730101)
- fix assertion in dbuf_verify (Bug ID 6752226)
- fix panic during zfs send with i/o errors (Bug ID 6577985)
- replace P2CROSS with P2BOUNDARY (Bug ID 6725680)

List of OpenSolaris Bug IDs:
6333409, 6418042, 6757112, 6725668, 6725675, 6725680,
6725698, 6729696, 6730101, 6752226, 6577985, 6755042

Approved by:	pjd, delphij (mentor)
Obtained from:	OpenSolaris (multiple Bug IDs)
MFC after:	1 week

1 files changed, 6 insertions, 4 deletions

diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/txg.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/txg.c
index 8650fa1..da1e83e 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/txg.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/txg.c
@@ -309,12 +309,14 @@ txg_sync_thread(void *arg)
 		uint64_t txg;
 
 		/*
-		 * We sync when there's someone waiting on us, or the
-		 * quiesce thread has handed off a txg to us, or we have
-		 * reached our timeout.
+		 * We sync when we're scrubbing, there's someone waiting
+		 * on us, or the quiesce thread has handed off a txg to
+		 * us, or we have reached our timeout.
 		 */
 		timer = (delta >= timeout ? 0 : timeout - delta);
-		while (!tx->tx_exiting && timer > 0 &&
+		while ((dp->dp_scrub_func == SCRUB_FUNC_NONE ||
+		    spa_shutting_down(dp->dp_spa)) &&
+		    !tx->tx_exiting && timer > 0 &&
 		    tx->tx_synced_txg >= tx->tx_sync_txg_waiting &&
 		    tx->tx_quiesced_txg == 0) {
 			dprintf("waiting; tx_synced=%llu waiting=%llu dp=%p\n",