xfs: realtime refcount btree transaction reservations

Source kernel commit: 2003c6a8754e307970c101a20baf8fb67d0588f2

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

diff --git a/libxfs/xfs_trans_resv.c b/libxfs/xfs_trans_resv.c
index cdfac7a12906c284a176435bf42757135408a560..4034c52790de8b97876671fc96f0bc963805dea2 100644 (file)
--- a/libxfs/xfs_trans_resv.c
+++ b/libxfs/xfs_trans_resv.c
@@ -89,6 +89,14 @@ 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
@@ -256,10 +264,13 @@ 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(
@@ -267,12 +278,20 @@ 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);
 }
 
 /*