[PATCH 05/42] xfs: realtime refcount btree transaction reservations

["Darrick J. Wong" <djwong@xxxxxxxxxx>]

From: Darrick J. Wong <djwong@xxxxxxxxxx>

Make sure that there's enough log reservation to handle mapping
and unmapping realtime extents.  We have to reserve enough space
to handle a split in the rtrefcountbt to add the record and a second
split in the regular refcountbt to record the rtrefcountbt split.

Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
 fs/xfs/libxfs/xfs_trans_resv.c |   25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)


diff --git a/fs/xfs/libxfs/xfs_trans_resv.c b/fs/xfs/libxfs/xfs_trans_resv.c
index 52a4386a3d96..2b8b8dd5dec3 100644
--- a/fs/xfs/libxfs/xfs_trans_resv.c
+++ b/fs/xfs/libxfs/xfs_trans_resv.c
@@ -90,6 +90,14 @@ xfs_refcountbt_block_count(
 	return num_ops * (2 * mp->m_refc_maxlevels - 1);
 }
 
+static unsigned int
+xfs_rtrefcountbt_block_count(
+	struct xfs_mount	*mp,
+	unsigned int		num_ops)
+{
+	return num_ops * (2 * mp->m_rtrefc_maxlevels - 1);
+}
+
 /*
  * Logging inodes is really tricksy. They are logged in memory format,
  * which means that what we write into the log doesn't directly translate into
@@ -257,10 +265,13 @@ xfs_rtalloc_block_count(
  * Compute the log reservation required to handle the refcount update
  * transaction.  Refcount updates are always done via deferred log items.
  *
- * This is calculated as:
+ * This is calculated as the max of:
  * Data device refcount updates (t1):
  *    the agfs of the ags containing the blocks: nr_ops * sector size
  *    the refcount btrees: nr_ops * 1 trees * (2 * max depth - 1) * block size
+ * Realtime refcount updates (t2);
+ *    the rt refcount inode
+ *    the rtrefcount btrees: nr_ops * 1 trees * (2 * max depth - 1) * block size
  */
 static unsigned int
 xfs_calc_refcountbt_reservation(
@@ -268,12 +279,20 @@ xfs_calc_refcountbt_reservation(
 	unsigned int		nr_ops)
 {
 	unsigned int		blksz = XFS_FSB_TO_B(mp, 1);
+	unsigned int		t1, t2 = 0;
 
 	if (!xfs_has_reflink(mp))
 		return 0;
 
-	return xfs_calc_buf_res(nr_ops, mp->m_sb.sb_sectsize) +
-	       xfs_calc_buf_res(xfs_refcountbt_block_count(mp, nr_ops), blksz);
+	t1 = xfs_calc_buf_res(nr_ops, mp->m_sb.sb_sectsize) +
+	     xfs_calc_buf_res(xfs_refcountbt_block_count(mp, nr_ops), blksz);
+
+	if (xfs_has_realtime(mp))
+		t2 = xfs_calc_inode_res(mp, 1) +
+		     xfs_calc_buf_res(xfs_rtrefcountbt_block_count(mp, nr_ops),
+				     blksz);
+
+	return max(t1, t2);
 }
 
 /*