4 files changed, 28 insertions, 27 deletions

diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index 638657a91335..e56991d1a970 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -1839,19 +1839,8 @@ void
 xfs_alloc_compute_maxlevels(
         xfs_mount_t     *mp)    /* file system mount structure */
 {
-        int             level;
-        uint            maxblocks;
-        uint            maxleafents;
-        int             minleafrecs;
-        int             minnoderecs;
-
-        maxleafents = (mp->m_sb.sb_agblocks + 1) / 2;
-        minleafrecs = mp->m_alloc_mnr[0];
-        minnoderecs = mp->m_alloc_mnr[1];
-        maxblocks = (maxleafents + minleafrecs - 1) / minleafrecs;
-        for (level = 1; maxblocks > 1; level++)
-                maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs;
-        mp->m_ag_maxlevels = level;
+        mp->m_ag_maxlevels = xfs_btree_compute_maxlevels(mp, mp->m_alloc_mnr,
+                        (mp->m_sb.sb_agblocks + 1) / 2);
 }
 
 /*
diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index 1f88e1ce770f..a6779b3e873c 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -4152,3 +4152,22 @@ xfs_btree_sblock_verify(
 
         return true;
 }
+
+/*
+ * Calculate the number of btree levels needed to store a given number of
+ * records in a short-format btree.
+ */
+uint
+xfs_btree_compute_maxlevels(
+        struct xfs_mount        *mp,
+        uint                    *limits,
+        unsigned long           len)
+{
+        uint                    level;
+        unsigned long           maxblocks;
+
+        maxblocks = (len + limits[0] - 1) / limits[0];
+        for (level = 1; maxblocks > 1; level++)
+                maxblocks = (maxblocks + limits[1] - 1) / limits[1];
+        return level;
+}
diff --git a/fs/xfs/libxfs/xfs_btree.h b/fs/xfs/libxfs/xfs_btree.h
index 2e874be70209..785a99682159 100644
--- a/fs/xfs/libxfs/xfs_btree.h
+++ b/fs/xfs/libxfs/xfs_btree.h
@@ -474,5 +474,7 @@ static inline int xfs_btree_get_level(struct xfs_btree_block *block)
 
 bool xfs_btree_sblock_v5hdr_verify(struct xfs_buf *bp);
 bool xfs_btree_sblock_verify(struct xfs_buf *bp, unsigned int max_recs);
+uint xfs_btree_compute_maxlevels(struct xfs_mount *mp, uint *limits,
+                                 unsigned long len);
 
 #endif  /* __XFS_BTREE_H__ */
diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c
index e3c0af73cf94..4b1e408169a8 100644
--- a/fs/xfs/libxfs/xfs_ialloc.c
+++ b/fs/xfs/libxfs/xfs_ialloc.c
@@ -2394,20 +2394,11 @@ void
 xfs_ialloc_compute_maxlevels(
         xfs_mount_t     *mp)            /* file system mount structure */
 {
-        int             level;
-        uint            maxblocks;
-        uint            maxleafents;
-        int             minleafrecs;
-        int             minnoderecs;
-
-        maxleafents = (1LL << XFS_INO_AGINO_BITS(mp)) >>
-                XFS_INODES_PER_CHUNK_LOG;
-        minleafrecs = mp->m_inobt_mnr[0];
-        minnoderecs = mp->m_inobt_mnr[1];
-        maxblocks = (maxleafents + minleafrecs - 1) / minleafrecs;
-        for (level = 1; maxblocks > 1; level++)
-                maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs;
-        mp->m_in_maxlevels = level;
+        uint            inodes;
+
+        inodes = (1LL << XFS_INO_AGINO_BITS(mp)) >> XFS_INODES_PER_CHUNK_LOG;
+        mp->m_in_maxlevels = xfs_btree_compute_maxlevels(mp, mp->m_inobt_mnr,
+                                                         inodes);
 }
 
 /*