[PATCH 13/37] xfs: add metadata reservations for realtime rmap btrees

Darrick J. Wong
2024-12-13T01:03:59Z

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 rmap btree.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
---
fs/xfs/libxfs/xfs_rtrmap_btree.c | 41 ++++++++++++++++++++++++++++++++++++++
fs/xfs/libxfs/xfs_rtrmap_btree.h | 2 ++
fs/xfs/xfs_rtalloc.c | 23 ++++++++++++++++++++-
3 files changed, 65 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/libxfs/xfs_rtrmap_btree.c b/fs/xfs/libxfs/xfs_rtrmap_btree.c
index 22aabf326b2ccd..08c4014a75a42c 100644
--- a/fs/xfs/libxfs/xfs_rtrmap_btree.c
+++ b/fs/xfs/libxfs/xfs_rtrmap_btree.c
@@ -540,3 +540,44 @@ xfs_rtrmapbt_compute_maxlevels(
/* Add one level to handle the inode root level. */
mp->m_rtrmap_maxlevels = min(d_maxlevels, r_maxlevels) + 1;
}
+
+/* Calculate the rtrmap btree size for some records. */
+static unsigned long long
+xfs_rtrmapbt_calc_size(
+ struct xfs_mount *mp,
+ unsigned long long len)
+{
+ return xfs_btree_calc_size(mp->m_rtrmap_mnr, len);
+}
+
+/*
+ * Calculate the maximum rmap btree size.
+ */
+static unsigned long long
+xfs_rtrmapbt_max_size(
+ struct xfs_mount *mp,
+ xfs_rtblock_t rtblocks)
+{
+ /* Bail out if we're uninitialized, which can happen in mkfs. */
+ if (mp->m_rtrmap_mxr[0] == 0)
+ return 0;
+
+ return xfs_rtrmapbt_calc_size(mp, rtblocks);
+}
+
+/*
+ * Figure out how many blocks to reserve and how many are used by this btree.
+ */
+xfs_filblks_t
+xfs_rtrmapbt_calc_reserves(
+ struct xfs_mount *mp)
+{
+ uint32_t blocks = mp->m_groups[XG_TYPE_RTG].blocks;
+
+ if (!xfs_has_rtrmapbt(mp))
+ return 0;
+
+ /* 1/64th (~1.5%) of the space, and enough for 1 record per block. */
+ return max_t(xfs_filblks_t, blocks >> 6,
+ xfs_rtrmapbt_max_size(mp, blocks));
+}
diff --git a/fs/xfs/libxfs/xfs_rtrmap_btree.h b/fs/xfs/libxfs/xfs_rtrmap_btree.h
index 63aabae2e09db1..ad5cb1078bc1a0 100644
--- a/fs/xfs/libxfs/xfs_rtrmap_btree.h
+++ b/fs/xfs/libxfs/xfs_rtrmap_btree.h
@@ -79,4 +79,6 @@ unsigned int xfs_rtrmapbt_maxlevels_ondisk(void);
int __init xfs_rtrmapbt_init_cur_cache(void);
void xfs_rtrmapbt_destroy_cur_cache(void);

+xfs_filblks_t xfs_rtrmapbt_calc_reserves(struct xfs_mount *mp);
+
#endif /* __XFS_RTRMAP_BTREE_H__ */
diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index 4cd2f32aa70a0a..2245f9ecaa3398 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -22,6 +22,7 @@
#include "xfs_rtalloc.h"
#include "xfs_sb.h"
#include "xfs_rtbitmap.h"
+#include "xfs_rtrmap_btree.h"
#include "xfs_quota.h"
#include "xfs_log_priv.h"
#include "xfs_health.h"
@@ -1498,6 +1499,13 @@ void
xfs_rt_resv_free(
struct xfs_mount *mp)
{
+ struct xfs_rtgroup *rtg = NULL;
+ unsigned int i;
+
+ while ((rtg = xfs_rtgroup_next(mp, rtg))) {
+ for (i = 0; i < XFS_RTGI_MAX; i++)
+ xfs_metafile_resv_free(rtg->rtg_inodes[i]);
+ }
}

/* Reserve space for rt metadata inodes' space expansion. */
@@ -1505,7 +1513,20 @@ int
xfs_rt_resv_init(
struct xfs_mount *mp)
{
- return 0;
+ struct xfs_rtgroup *rtg = NULL;
+ xfs_filblks_t ask;
+ int error = 0;
+
+ while ((rtg = xfs_rtgroup_next(mp, rtg))) {
+ int err2;
+
+ ask = xfs_rtrmapbt_calc_reserves(mp);
+ err2 = xfs_metafile_resv_init(rtg_rmap(rtg), ask);
+ if (err2 && !error)
+ error = err2;
+ }
+
+ return error;
}

/*