xfs: don't reserve per-AG space for an internal log

[linux.git] / fs / xfs / libxfs / xfs_ialloc_btree.c

diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.c b/fs/xfs/libxfs/xfs_ialloc_btree.c
index 1080381ff243e68ee3b6c89fef1e2e78341d8994..bc2dfacd2f4a01c83864361862442ab63c4a73b2 100644 (file)
--- a/fs/xfs/libxfs/xfs_ialloc_btree.c
+++ b/fs/xfs/libxfs/xfs_ialloc_btree.c
@@ -549,6 +549,15 @@ xfs_inobt_max_size(
        if (mp->m_inobt_mxr[0] == 0)
                return 0;
 
+       /*
+        * The log is permanently allocated, so the space it occupies will
+        * never be available for the kinds of things that would require btree
+        * expansion.  We therefore can pretend the space isn't there.
+        */
+       if (mp->m_sb.sb_logstart &&
+           XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart) == agno)
+               agblocks -= mp->m_sb.sb_logblocks;
+
        return xfs_btree_calc_size(mp->m_inobt_mnr,
                                (uint64_t)agblocks * mp->m_sb.sb_inopblock /
                                        XFS_INODES_PER_CHUNK);