space_reftree.c revision 9a686fbc186e8e2a64e9a5094d44c7d6fa0ea167
/*
* CDDL HEADER START
*
* 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
* 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]
*
* CDDL HEADER END
*/
/*
* Copyright 2009 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* Copyright (c) 2013, 2015 by Delphix. All rights reserved.
*/
#include <sys/zfs_context.h>
#include <sys/range_tree.h>
#include <sys/space_reftree.h>
/*
* Space reference trees.
*
* A range tree is a collection of integers. Every integer is either
* in the tree, or it's not. A space reference tree generalizes
* the idea: it allows its members to have arbitrary reference counts,
* as opposed to the implicit reference count of 0 or 1 in a range tree.
* This representation comes in handy when computing the union or
* intersection of multiple space maps. For example, the union of
* N range trees is the subset of the reference tree with refcnt >= 1.
* The intersection of N range trees is the subset with refcnt >= N.
*
* [It's very much like a Fourier transform. Unions and intersections
* are hard to perform in the 'range tree domain', so we convert the trees
* into the 'reference count domain', where it's trivial, then invert.]
*
* vdev_dtl_reassess() uses computations of this form to determine
* DTL_MISSING and DTL_OUTAGE for interior vdevs -- e.g. a RAID-Z vdev
* has an outage wherever refcnt >= vdev_nparity + 1, and a mirror vdev
* has an outage wherever refcnt >= vdev_children.
*/
static int
{
return (-1);
return (1);
return (-1);
return (1);
return (0);
}
void
{
}
void
{
avl_destroy(t);
}
static void
{
}
void
{
}
/*
* Convert (or add) a range tree into a reference tree.
*/
void
{
}
/*
* Convert a reference tree into a range tree. The range tree will contain
* all members of the reference tree for which refcnt >= minref.
*/
void
{
if (start == -1ULL) {
}
} else {
if (start != -1ULL) {
start = -1ULL;
}
}
}
}