xfs: add metadata reservations for realtime refcount btree

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>
Reviewed-by: Christoph Hellwig <hch@lst.de>

diff --git a/fs/xfs/libxfs/xfs_rtrefcount_btree.c b/fs/xfs/libxfs/xfs_rtrefcount_btree.c
index ebbeab112d141255f05b41118dab0697419cec00..ff72ed09e75f0876f44e0f56e225323d8d31b8ef 100644 (file)
--- 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 b713b33818800c66a1879e56f8245d975e99defe..3cd44590c9304c599acba0d7cf216d16120ae225 100644 (file)
--- 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 a69967f9d88ead37e860e01a63b1ee71423f0f72..294aa0739be311ee0606f22f9c81e655af823930 100644 (file)
--- 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;