Add a new "REFCOMPRESSRATIO" property.

For snapshots, this is the same as COMPRESSRATIO, but for
filesystems/volumes, the COMPRESSRATIO is based on the data "USED" (ie,
includes blocks in children, but not blocks shared with the origin).

This is needed to figure out how much space a filesystem would use if it
were not compressed (ignoring snapshots).

Illumos-gate revision:	13387

Obtained from:	Illumos (Feature #1092)
MFC after:	2 weeks

2 files changed, 16 insertions, 2 deletions

diff --git a/cddl/contrib/opensolaris/cmd/zfs/zfs.8 b/cddl/contrib/opensolaris/cmd/zfs/zfs.8
index 0d40a9083c7e..e5d859001e1f 100644
--- a/cddl/contrib/opensolaris/cmd/zfs/zfs.8
+++ b/cddl/contrib/opensolaris/cmd/zfs/zfs.8
@@ -6,6 +6,7 @@
 .\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License. You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.
 .\"  See the License for the specific language governing permissions and limitations under the License. When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE.  If applicable, add the following below this CDDL HEADER, with
 .\" the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
+.\" Copyright 2011 by Delphix.  All rights reserved.
 .TH zfs 1M "24 Sep 2009" "SunOS 5.11" "System Administration Commands"
 .SH NAME
 zfs \- configures ZFS file systems
@@ -389,7 +390,7 @@ This property can also be referred to by its shortened column name, \fBavail\fR.
 .ad
 .sp .6
 .RS 4n
-The compression ratio achieved for this dataset, expressed as a multiplier. Compression can be turned on by running: \fBzfs set compression=on \fIdataset\fR\fR. The default value is \fBoff\fR.
+For non-snapshots, the compression ratio achieved for the \fBused\fR space of this dataset, expressed as a multiplier.  The \fBused\fR property includes descendant datasets, and, for clones, does not include the space shared with the origin snapshot.  For snapshots, the \fBcompressratio\fR is the same as the \fBrefcompressratio\fR property. Compression can be turned on by running: \fBzfs set compression=on \fIdataset\fR\fR. The default value is \fBoff\fR.
 .RE
 
 .sp
@@ -453,6 +454,17 @@ This property can also be referred to by its shortened column name, \fBrefer\fR.
 .ne 2
 .mk
 .na
+\fB\fBrefcompressratio\fR\fR
+.ad
+.sp .6
+.RS 4n
+The compression ratio achieved for the \fBreferenced\fR space of this dataset, expressed as a multiplier.  See also the \fBcompressratio\fR property.
+.RE
+
+.sp
+.ne 2
+.mk
+.na
 \fB\fBtype\fR\fR
 .ad
 .sp .6
@@ -1278,7 +1290,7 @@ Recursively destroy all dependents, including cloned file systems outside the ta
 Force an unmount of any file systems using the \fBunmount -f\fR command. This option has no effect on non-file systems or unmounted file systems.
 .RE
 
-Extreme care should be taken when applying either the \fB-r\fR or the \fB-f\fR options, as they can destroy large portions of a pool and cause unexpected behavior for mounted file systems in use. 
+Extreme care should be taken when applying either the \fB-r\fR or the \fB-R\fR options, as they can destroy large portions of a pool and cause unexpected behavior for mounted file systems in use. 
 .RE
 
 .sp
diff --git a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c
index 824834e46766..82f4925bd329 100644
--- a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c
+++ b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c
@@ -22,6 +22,7 @@
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2010 Nexenta Systems, Inc. All rights reserved.
+ * Copyright (c) 2011 by Delphix. All rights reserved.
  */
 
 #include <ctype.h>
@@ -2038,6 +2039,7 @@ zfs_prop_get(zfs_handle_t *zhp, zfs_prop_t prop, char *propbuf, size_t proplen,
 		}
 		break;
 
+	case ZFS_PROP_REFRATIO:
 	case ZFS_PROP_COMPRESSRATIO:
 		if (get_numeric_property(zhp, prop, src, &source, &val) != 0)
 			return (-1);