[PATCH 11/43] xfs: add metadata reservations for realtime refcount btree

Darrick J. Wong
2024-12-13T01:13:07Z

From: Darrick J. Wong <djwong@kernel.org>

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@kernel.org>
---
fs/xfs/libxfs/xfs_rtrefcount_btree.c | 38 ++++++++++++++++++++++++++++++++++
fs/xfs/libxfs/xfs_rtrefcount_btree.h | 4 ++++
fs/xfs/xfs_rtalloc.c | 6 +++++
3 files changed, 48 insertions(+)

diff --git a/fs/xfs/libxfs/xfs_rtrefcount_btree.c b/fs/xfs/libxfs/xfs_rtrefcount_btree.c
index ebbeab112d1412..ff72ed09e75f08 100644
--- a/fs/xfs/libxfs/xfs_rtrefcount_btree.c
+++ b/fs/xfs/libxfs/xfs_rtrefcount_btree.c
@@ -419,3 +419,41 @@ xfs_rtrefcountbt_compute_maxlevels(
/* Add one level to handle the inode root level. */
mp->m_rtrefc_maxlevels = min(d_maxlevels, r_maxlevels) + 1;
}
+
+/* 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, mp->m_sb.sb_rgextents);
+}
diff --git a/fs/xfs/libxfs/xfs_rtrefcount_btree.h b/fs/xfs/libxfs/xfs_rtrefcount_btree.h
index b713b33818800c..3cd44590c9304c 100644
--- a/fs/xfs/libxfs/xfs_rtrefcount_btree.h
+++ b/fs/xfs/libxfs/xfs_rtrefcount_btree.h
@@ -67,4 +67,8 @@ unsigned int xfs_rtrefcountbt_maxlevels_ondisk(void);
int __init xfs_rtrefcountbt_init_cur_cache(void);
void xfs_rtrefcountbt_destroy_cur_cache(void);

+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__ */
diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index a69967f9d88ead..294aa0739be311 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -31,6 +31,7 @@
#include "xfs_rtgroup.h"
#include "xfs_error.h"
#include "xfs_trace.h"
+#include "xfs_rtrefcount_btree.h"

/*
* Return whether there are any free extents in the size range given
@@ -1547,6 +1548,11 @@ xfs_rt_resv_init(
err2 = xfs_metafile_resv_init(rtg_rmap(rtg), ask);
if (err2 && !error)
error = err2;
+
+ ask = xfs_rtrefcountbt_calc_reserves(mp);
+ err2 = xfs_metafile_resv_init(rtg_refcount(rtg), ask);
+ if (err2 && !error)
+ error = err2;
}

return error;