From: Darrick J. Wong <djwong@xxxxxxxxxx>
Reserve some free blocks so that we will always have enough free blocks
in the data volume to handle expansion of the realtime refcount btree.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
libxfs/xfs_rtrefcount_btree.c | 39 +++++++++++++++++++++++++++++++++++++++
libxfs/xfs_rtrefcount_btree.h | 4 ++++
2 files changed, 43 insertions(+)
diff --git a/libxfs/xfs_rtrefcount_btree.c b/libxfs/xfs_rtrefcount_btree.c
index 425a56578c6..99eac508cda 100644
--- a/libxfs/xfs_rtrefcount_btree.c
+++ b/libxfs/xfs_rtrefcount_btree.c
@@ -489,3 +489,42 @@ xfs_rtrefcountbt_create_path(
*pathp = path;
return 0;
}
+
+/* Calculate the rtrefcount btree size for some records. */
+unsigned long long
+xfs_rtrefcountbt_calc_size(
+ struct xfs_mount *mp,
+ unsigned long long len)
+{
+ return xfs_btree_calc_size(mp->m_rtrefc_mnr, len);
+}
+
+/*
+ * Calculate the maximum refcount btree size.
+ */
+static unsigned long long
+xfs_rtrefcountbt_max_size(
+ struct xfs_mount *mp,
+ xfs_rtblock_t rtblocks)
+{
+ /* Bail out if we're uninitialized, which can happen in mkfs. */
+ if (mp->m_rtrefc_mxr[0] == 0)
+ return 0;
+
+ return xfs_rtrefcountbt_calc_size(mp, rtblocks);
+}
+
+/*
+ * Figure out how many blocks to reserve and how many are used by this btree.
+ * We need enough space to hold one record for every rt extent in the rtgroup.
+ */
+xfs_filblks_t
+xfs_rtrefcountbt_calc_reserves(
+ struct xfs_mount *mp)
+{
+ if (!xfs_has_rtreflink(mp))
+ return 0;
+
+ return xfs_rtrefcountbt_max_size(mp,
+ xfs_rtb_to_rtx(mp, mp->m_sb.sb_rgblocks));
+}
diff --git a/libxfs/xfs_rtrefcount_btree.h b/libxfs/xfs_rtrefcount_btree.h
index ff49e95d1a4..045f7b1f728 100644
--- a/libxfs/xfs_rtrefcount_btree.h
+++ b/libxfs/xfs_rtrefcount_btree.h
@@ -72,4 +72,8 @@ void xfs_rtrefcountbt_destroy_cur_cache(void);
int xfs_rtrefcountbt_create_path(struct xfs_mount *mp, xfs_rgnumber_t rgno,
struct xfs_imeta_path **pathp);
+xfs_filblks_t xfs_rtrefcountbt_calc_reserves(struct xfs_mount *mp);
+unsigned long long xfs_rtrefcountbt_calc_size(struct xfs_mount *mp,
+ unsigned long long len);
+
#endif /* __XFS_RTREFCOUNT_BTREE_H__ */
