xfs: add metadata reservations for realtime rmap btrees

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>

diff --git a/libxfs/xfs_metafile.c b/libxfs/xfs_metafile.c
index 435b8f8bf6b8189a61a845988eeeade84421f885..ce0e61f023f85a26d605eccaccc097e9f9334180 100644 (file)
--- a/libxfs/xfs_metafile.c
+++ b/libxfs/xfs_metafile.c
@@ -202,7 +202,11 @@ void
 xfs_metafile_resv_free(
        struct xfs_inode        *ip)
 {
-       if (!ip)
+       /*
+        * We can end up here for the rt bitmap/summary inodes that don't have
+        * reservations.  Just exist early in that case.
+        */
+       if (!ip || !ip->i_delayed_blks)
                return;
 
        ASSERT(xfs_is_metadir_inode(ip));

diff --git a/libxfs/xfs_rtrmap_btree.c b/libxfs/xfs_rtrmap_btree.c
index 6e780f1bd9663d49eccf78d7adaed5df11254713..93ab59ff027e04f394772e42ac736a4a5d819a04 100644 (file)
--- a/libxfs/xfs_rtrmap_btree.c
+++ b/libxfs/xfs_rtrmap_btree.c
@@ -539,3 +539,44 @@ 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/libxfs/xfs_rtrmap_btree.h b/libxfs/xfs_rtrmap_btree.h
index 63aabae2e09db1eb6e733f2e3b3deec614e39e3e..ad5cb1078bc1a002e8d903f23484af9202b62869 100644 (file)
--- a/libxfs/xfs_rtrmap_btree.h
+++ b/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__ */