From: Darrick J. Wong <darrick.wong@oracle.com>
Date: Tue, 25 Oct 2016 01:26:50 +0000 (+1100)
Subject: xfs: reserve AG space for the refcount btree root
X-Git-Tag: v4.9.0-rc1~101
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=868c70e32419482478fa99d4f8e0bb5960656e61;p=thirdparty%2Fxfsprogs-dev.git

xfs: reserve AG space for the refcount btree root

Source kernel commit: d0e853f3600cd2a3f7c4a067dc38155c77c51df9

Reduce the max AG usable space size so that we always have space for
the refcount btree root.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---

diff --git a/libxfs/xfs_alloc.c b/libxfs/xfs_alloc.c
index 84f1e14df..1ca326857 100644
--- a/libxfs/xfs_alloc.c
+++ b/libxfs/xfs_alloc.c
@@ -124,6 +124,8 @@ xfs_alloc_ag_max_usable(
 		blocks++;		/* finobt root block */
 	if (xfs_sb_version_hasrmapbt(&mp->m_sb))
 		blocks++; 		/* rmap root block */
+	if (xfs_sb_version_hasreflink(&mp->m_sb))
+		blocks++;		/* refcount root block */
 
 	return mp->m_sb.sb_agblocks - blocks;
 }