Illumos #2619 and #2747

2619 asynchronous destruction of ZFS file systems
2747 SPA versioning with zfs feature flags
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <gwilson@delphix.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Reviewed by: Dan Kruchinin <dan.kruchinin@gmail.com>
Approved by: Eric Schrock <Eric.Schrock@delphix.com>

References:
  illumos/illumos-gate@53089ab7c8
  illumos/illumos-gate@ad135b5d64
  illumos changeset: 13700:2889e2596bd6
  https://www.illumos.org/issues/2619
  https://www.illumos.org/issues/2747

NOTE: The grub specific changes were not ported.  This change
must be made to the Linux grub packages.

Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

include/sys/zio.h

@@ -24,6 +24,7 @@
  */
 /*
  * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
+ * Copyright (c) 2012 by Delphix. All rights reserved.
  */
 
 #ifndef _ZIO_H
@@ -278,6 +279,14 @@ typedef struct zbookmark {
 #define	ZB_ZIL_OBJECT		(0ULL)
 #define	ZB_ZIL_LEVEL		(-2LL)
 
+#define	ZB_IS_ZERO(zb)						\
+	((zb)->zb_objset == 0 && (zb)->zb_object == 0 &&	\
+	(zb)->zb_level == 0 && (zb)->zb_blkid == 0)
+#define	ZB_IS_ROOT(zb)				\
+	((zb)->zb_object == ZB_ROOT_OBJECT &&	\
+	(zb)->zb_level == ZB_ROOT_LEVEL &&	\
+	(zb)->zb_blkid == ZB_ROOT_BLKID)
+
 typedef struct zio_prop {
 	enum zio_checksum	zp_checksum;
 	enum zio_compress	zp_compress;
@@ -295,6 +304,7 @@ typedef void zio_cksum_finish_f(zio_cksum_report_t *rep,
 typedef void zio_cksum_free_f(void *cbdata, size_t size);
 
 struct zio_bad_cksum;				/* defined in zio_checksum.h */
+struct dnode_phys;
 
 struct zio_cksum_report {
 	struct zio_cksum_report *zcr_next;
@@ -567,6 +577,10 @@ extern void zfs_ereport_post_checksum(spa_t *spa, vdev_t *vd,
 /* Called from spa_sync(), but primarily an injection handler */
 extern void spa_handle_ignored_writes(spa_t *spa);
 
+/* zbookmark functions */
+boolean_t zbookmark_is_before(const struct dnode_phys *dnp,
+    const zbookmark_t *zb1, const zbookmark_t *zb2);
+
 #ifdef	__cplusplus
 }
 #endif