diff --git a/fs/xfs/libxfs/xfs_alloc_btree.c b/fs/xfs/libxfs/xfs_alloc_btree.c
index c644b11..7f8612e 100644
--- a/fs/xfs/libxfs/xfs_alloc_btree.c
+++ b/fs/xfs/libxfs/xfs_alloc_btree.c
@@ -582,6 +582,18 @@ xfs_allocbt_maxrecs(
 	return blocklen / (sizeof(xfs_alloc_key_t) + sizeof(xfs_alloc_ptr_t));
 }
 
+unsigned int
+xfs_allocbt_absolute_maxlevels(void)
+{
+	unsigned int		minrecs[2];
+
+	xfs_btree_absolute_minrecs(minrecs, 0, sizeof(xfs_alloc_rec_t),
+			sizeof(xfs_alloc_key_t) + sizeof(xfs_alloc_ptr_t));
+
+	return xfs_btree_compute_maxlevels(minrecs,
+			(XFS_MAX_AG_BLOCKS + 1) / 2);
+}
+
 /* Calculate the freespace btree size for some records. */
 xfs_extlen_t
 xfs_allocbt_calc_size(
diff --git a/fs/xfs/libxfs/xfs_alloc_btree.h b/fs/xfs/libxfs/xfs_alloc_btree.h
index 2f6b816..0d5b9ae 100644
--- a/fs/xfs/libxfs/xfs_alloc_btree.h
+++ b/fs/xfs/libxfs/xfs_alloc_btree.h
@@ -59,5 +59,6 @@ extern xfs_extlen_t xfs_allocbt_calc_size(struct xfs_mount *mp,
 
 void xfs_allocbt_commit_staged_btree(struct xfs_btree_cur *cur,
 		struct xfs_trans *tp, struct xfs_buf *agbp);
+unsigned int xfs_allocbt_absolute_maxlevels(void);
 
 #endif	/* __XFS_ALLOC_BTREE_H__ */
diff --git a/fs/xfs/libxfs/xfs_bmap_btree.c b/fs/xfs/libxfs/xfs_bmap_btree.c
index a06987e..976a324 100644
--- a/fs/xfs/libxfs/xfs_bmap_btree.c
+++ b/fs/xfs/libxfs/xfs_bmap_btree.c
@@ -586,6 +586,19 @@ xfs_bmbt_maxrecs(
 	return blocklen / (sizeof(xfs_bmbt_key_t) + sizeof(xfs_bmbt_ptr_t));
 }
 
+unsigned int
+xfs_bmbt_absolute_maxlevels(void)
+{
+	unsigned int		minrecs[2];
+
+	xfs_btree_absolute_minrecs(minrecs, XFS_BTREE_LONG_PTRS,
+			sizeof(struct xfs_bmbt_rec),
+			sizeof(struct xfs_bmbt_key) +
+				sizeof(xfs_bmbt_ptr_t));
+
+	return xfs_btree_compute_maxlevels(minrecs, MAXEXTNUM) + 1;
+}
+
 /*
  * Calculate number of records in a bmap btree inode root.
  */
diff --git a/fs/xfs/libxfs/xfs_bmap_btree.h b/fs/xfs/libxfs/xfs_bmap_btree.h
index 729e3bc..1c51689 100644
--- a/fs/xfs/libxfs/xfs_bmap_btree.h
+++ b/fs/xfs/libxfs/xfs_bmap_btree.h
@@ -109,5 +109,6 @@ extern struct xfs_btree_cur *xfs_bmbt_init_cursor(struct xfs_mount *,
 
 extern unsigned long long xfs_bmbt_calc_size(struct xfs_mount *mp,
 		unsigned long long len);
+unsigned int xfs_bmbt_absolute_maxlevels(void);
 
 #endif	/* __XFS_BMAP_BTREE_H__ */
diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index 619319f..120280c 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -27,6 +27,13 @@
  * Cursor allocation zone.
  */
 kmem_zone_t	*xfs_btree_cur_zone;
+struct xfs_btree_cur_zone xfs_btree_cur_zones[XFS_BTNUM_MAX] = {
+	[XFS_BTNUM_BNO]		= { .name = "xfs_alloc_btree_cur" },
+	[XFS_BTNUM_INO]		= { .name = "xfs_ialloc_btree_cur" },
+	[XFS_BTNUM_RMAP]	= { .name = "xfs_rmap_btree_cur" },
+	[XFS_BTNUM_REFC]	= { .name = "xfs_refc_btree_cur" },
+	[XFS_BTNUM_BMAP]	= { .name = "xfs_bmap_btree_cur" },
+};
 
 /*
  * Btree magic numbers.
@@ -5027,3 +5034,44 @@ xfs_btree_alloc_cursor(
 
 	return cur;
 }
+
+/*
+ * Compute absolute minrecs for leaf and node btree blocks.  Callers should set
+ * BTREE_LONG_PTRS and BTREE_OVERLAPPING as they would for regular cursors.
+ * Set BTREE_CRC_BLOCKS if the btree type is supported on V5 or newer
+ * filesystems.
+ */
+void
+xfs_btree_absolute_minrecs(
+	unsigned int		*minrecs,
+	unsigned int		bc_flags,
+	unsigned int		leaf_recbytes,
+	unsigned int		node_recbytes)
+{
+	unsigned int		min_recbytes;
+
+	/*
+	 * If this btree type is supported on V4, we use the smaller V4 min
+	 * block size along with the V4 header size.  If the btree type is only
+	 * supported on V5, use the (twice as large) V5 min block size along
+	 * with the V5 header size.
+	 */
+	if (!(bc_flags & XFS_BTREE_CRC_BLOCKS)) {
+		if (bc_flags & XFS_BTREE_LONG_PTRS)
+			min_recbytes = XFS_MIN_BLOCKSIZE -
+							XFS_BTREE_LBLOCK_LEN;
+		else
+			min_recbytes = XFS_MIN_BLOCKSIZE -
+							XFS_BTREE_SBLOCK_LEN;
+	} else if (bc_flags & XFS_BTREE_LONG_PTRS) {
+		min_recbytes = XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_LBLOCK_CRC_LEN;
+	} else {
+		min_recbytes = XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN;
+	}
+
+	if (bc_flags & XFS_BTREE_OVERLAPPING)
+		node_recbytes <<= 1;
+
+	minrecs[0] = min_recbytes / (2 * leaf_recbytes);
+	minrecs[1] = min_recbytes / (2 * node_recbytes);
+}
diff --git a/fs/xfs/libxfs/xfs_btree.h b/fs/xfs/libxfs/xfs_btree.h
index 57b7aa3..5bebd26 100644
--- a/fs/xfs/libxfs/xfs_btree.h
+++ b/fs/xfs/libxfs/xfs_btree.h
@@ -583,4 +583,14 @@ struct xfs_btree_cur *xfs_btree_alloc_cursor(struct xfs_mount *mp,
 		struct xfs_trans *tp, xfs_btnum_t btnum);
 unsigned int xfs_btree_maxlevels(struct xfs_mount *mp, xfs_btnum_t btnum);
 
+void xfs_btree_absolute_minrecs(unsigned int *minrecs, unsigned int bc_flags,
+		unsigned int leaf_recbytes, unsigned int node_recbytes);
+
+struct xfs_btree_cur_zone {
+	const char		*name;
+	unsigned int		maxlevels;
+};
+
+extern struct xfs_btree_cur_zone xfs_btree_cur_zones[XFS_BTNUM_MAX];
+
 #endif	/* __XFS_BTREE_H__ */
diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
index bde2b4c..33d323d 100644
--- a/fs/xfs/libxfs/xfs_fs.h
+++ b/fs/xfs/libxfs/xfs_fs.h
@@ -268,6 +268,9 @@ typedef struct xfs_fsop_resblks {
  */
 #define XFS_MIN_AG_BYTES	(1ULL << 24)	/* 16 MB */
 #define XFS_MAX_AG_BYTES	(1ULL << 40)	/* 1 TB */
+#define XFS_MAX_AG_BLOCKS	(XFS_MAX_AG_BYTES / XFS_MIN_BLOCKSIZE)
+#define XFS_MAX_CRC_AG_BLOCKS	(XFS_MAX_AG_BYTES / XFS_MIN_CRC_BLOCKSIZE)
+#define XFS_MAX_AG_INODES	(XFS_MAX_AG_BYTES / XFS_DINODE_MIN_SIZE)
 
 /* keep the maximum size under 2^31 by a small amount */
 #define XFS_MAX_LOG_BYTES \
diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.c b/fs/xfs/libxfs/xfs_ialloc_btree.c
index c8fea6a..ce428c9 100644
--- a/fs/xfs/libxfs/xfs_ialloc_btree.c
+++ b/fs/xfs/libxfs/xfs_ialloc_btree.c
@@ -541,6 +541,17 @@ xfs_inobt_maxrecs(
 	return blocklen / (sizeof(xfs_inobt_key_t) + sizeof(xfs_inobt_ptr_t));
 }
 
+unsigned int
+xfs_inobt_absolute_maxlevels(void)
+{
+	unsigned int		minrecs[2];
+
+	xfs_btree_absolute_minrecs(minrecs, 0, sizeof(xfs_inobt_rec_t),
+			sizeof(xfs_inobt_key_t) + sizeof(xfs_inobt_ptr_t));
+
+	return xfs_btree_compute_maxlevels(minrecs, XFS_MAX_AG_INODES);
+}
+
 /*
  * Convert the inode record holemask to an inode allocation bitmap. The inode
  * allocation bitmap is inode granularity and specifies whether an inode is
diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.h b/fs/xfs/libxfs/xfs_ialloc_btree.h
index 8a322d4..e29570b 100644
--- a/fs/xfs/libxfs/xfs_ialloc_btree.h
+++ b/fs/xfs/libxfs/xfs_ialloc_btree.h
@@ -74,5 +74,6 @@ int xfs_inobt_cur(struct xfs_mount *mp, struct xfs_trans *tp,
 
 void xfs_inobt_commit_staged_btree(struct xfs_btree_cur *cur,
 		struct xfs_trans *tp, struct xfs_buf *agbp);
+unsigned int xfs_inobt_absolute_maxlevels(void);
 
 #endif	/* __XFS_IALLOC_BTREE_H__ */
diff --git a/fs/xfs/libxfs/xfs_refcount_btree.c b/fs/xfs/libxfs/xfs_refcount_btree.c
index 48c45e3..9d428c3 100644
--- a/fs/xfs/libxfs/xfs_refcount_btree.c
+++ b/fs/xfs/libxfs/xfs_refcount_btree.c
@@ -408,6 +408,19 @@ xfs_refcountbt_maxrecs(
 			   sizeof(xfs_refcount_ptr_t));
 }
 
+unsigned int
+xfs_refcountbt_absolute_maxlevels(void)
+{
+	unsigned int		minrecs[2];
+
+	xfs_btree_absolute_minrecs(minrecs, XFS_BTREE_CRC_BLOCKS,
+			sizeof(struct xfs_refcount_rec),
+			sizeof(struct xfs_refcount_key) +
+						sizeof(xfs_refcount_ptr_t));
+
+	return xfs_btree_compute_maxlevels(minrecs, XFS_MAX_CRC_AG_BLOCKS);
+}
+
 /* Compute the maximum height of a refcount btree. */
 void
 xfs_refcountbt_compute_maxlevels(
diff --git a/fs/xfs/libxfs/xfs_refcount_btree.h b/fs/xfs/libxfs/xfs_refcount_btree.h
index bd9ed9e..d7dad2d 100644
--- a/fs/xfs/libxfs/xfs_refcount_btree.h
+++ b/fs/xfs/libxfs/xfs_refcount_btree.h
@@ -64,5 +64,6 @@ extern int xfs_refcountbt_calc_reserves(struct xfs_mount *mp,
 
 void xfs_refcountbt_commit_staged_btree(struct xfs_btree_cur *cur,
 		struct xfs_trans *tp, struct xfs_buf *agbp);
+unsigned int xfs_refcountbt_absolute_maxlevels(void);
 
 #endif	/* __XFS_REFCOUNT_BTREE_H__ */
diff --git a/fs/xfs/libxfs/xfs_rmap_btree.c b/fs/xfs/libxfs/xfs_rmap_btree.c
index 85caeb1..d73768c 100644
--- a/fs/xfs/libxfs/xfs_rmap_btree.c
+++ b/fs/xfs/libxfs/xfs_rmap_btree.c
@@ -534,6 +534,31 @@ xfs_rmapbt_maxrecs(
 		(2 * sizeof(struct xfs_rmap_key) + sizeof(xfs_rmap_ptr_t));
 }
 
+unsigned int
+xfs_rmapbt_absolute_maxlevels(void)
+{
+	unsigned int		minrecs[2];
+
+	xfs_btree_absolute_minrecs(minrecs,
+			XFS_BTREE_CRC_BLOCKS | XFS_BTREE_OVERLAPPING,
+			sizeof(struct xfs_rmap_rec),
+			sizeof(struct xfs_rmap_key) + sizeof(xfs_rmap_ptr_t));
+
+	/*
+	 * Compute the asymptotic maxlevels for an rmapbt on any reflink fs.
+	 *
+	 * On a reflink filesystem, each AG block can have up to 2^32 (per the
+	 * refcount record format) owners, which means that theoretically we
+	 * could face up to 2^64 rmap records.  However, we're likely to run
+	 * out of blocks in the AG long before that happens, which means that
+	 * we must compute the max height based on what the btree will look
+	 * like if it consumes almost all the blocks in the AG due to maximal
+	 * sharing factor.
+	 */
+	return xfs_btree_compute_maxlevels_size(XFS_MAX_CRC_AG_BLOCKS,
+			minrecs[1]);
+}
+
 /* Compute the maximum height of an rmap btree. */
 unsigned int
 xfs_rmapbt_compute_maxlevels(
diff --git a/fs/xfs/libxfs/xfs_rmap_btree.h b/fs/xfs/libxfs/xfs_rmap_btree.h
index 5aaecf7..6d5001e 100644
--- a/fs/xfs/libxfs/xfs_rmap_btree.h
+++ b/fs/xfs/libxfs/xfs_rmap_btree.h
@@ -58,5 +58,6 @@ extern xfs_extlen_t xfs_rmapbt_max_size(struct xfs_mount *mp,
 
 extern int xfs_rmapbt_calc_reserves(struct xfs_mount *mp, struct xfs_trans *tp,
 		struct xfs_perag *pag, xfs_extlen_t *ask, xfs_extlen_t *used);
+unsigned int xfs_rmapbt_absolute_maxlevels(void);
 
 #endif /* __XFS_RMAP_BTREE_H__ */
diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h
index b6da06b..6ce15a4 100644
--- a/fs/xfs/libxfs/xfs_types.h
+++ b/fs/xfs/libxfs/xfs_types.h
@@ -126,6 +126,9 @@ typedef enum {
 	XFS_BTNUM_INOi, XFS_BTNUM_FINOi, XFS_BTNUM_REFCi, XFS_BTNUM_MAX
 } xfs_btnum_t;
 
+#define for_each_xfs_btnum(btnum) \
+	for((btnum) = XFS_BTNUM_BNOi; (btnum) < XFS_BTNUM_MAX; (btnum)++)
+
 #define XFS_BTNUM_STRINGS \
 	{ XFS_BTNUM_BNOi,	"bnobt" }, \
 	{ XFS_BTNUM_CNTi,	"cntbt" }, \
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 90c92a6..83abe9b 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -37,6 +37,12 @@
 #include "xfs_reflink.h"
 #include "xfs_pwork.h"
 #include "xfs_ag.h"
+#include "xfs_btree.h"
+#include "xfs_alloc_btree.h"
+#include "xfs_ialloc_btree.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_rmap_btree.h"
+#include "xfs_refcount_btree.h"
 
 #include <linux/magic.h>
 #include <linux/fs_context.h>
@@ -1951,8 +1957,33 @@ static struct file_system_type xfs_fs_type = {
 MODULE_ALIAS_FS("xfs");
 
 STATIC int __init
+xfs_init_btree_zones(void)
+{
+	struct xfs_btree_cur_zone	*z = xfs_btree_cur_zones;
+	xfs_btnum_t			btnum;
+
+	z[XFS_BTNUM_BNO].maxlevels	= xfs_allocbt_absolute_maxlevels();
+	z[XFS_BTNUM_RMAP].maxlevels	= xfs_rmapbt_absolute_maxlevels();
+	z[XFS_BTNUM_BMAP].maxlevels	= xfs_bmbt_absolute_maxlevels();
+	z[XFS_BTNUM_INO].maxlevels	= xfs_inobt_absolute_maxlevels();
+	z[XFS_BTNUM_REFC].maxlevels	= xfs_refcountbt_absolute_maxlevels();
+
+	for_each_xfs_btnum(btnum) {
+		ASSERT(z[btnum].maxlevels <= XFS_BTREE_CUR_ZONE_MAXLEVELS);
+	}
+
+	/* struct copies for btree types that share zones */
+	z[XFS_BTNUM_CNT] = z[XFS_BTNUM_BNO];
+	z[XFS_BTNUM_FINO] = z[XFS_BTNUM_INO];
+
+	return 0;
+}
+
+STATIC int __init
 xfs_init_zones(void)
 {
+	int			error;
+
 	xfs_log_ticket_zone = kmem_cache_create("xfs_log_ticket",
 						sizeof(struct xlog_ticket),
 						0, 0, NULL);
@@ -1965,6 +1996,10 @@ xfs_init_zones(void)
 	if (!xfs_bmap_free_item_zone)
 		goto out_destroy_log_ticket_zone;
 
+	error = xfs_init_btree_zones();
+	if (error)
+		goto out_destroy_bmap_free_item_zone;
+
 	xfs_btree_cur_zone = kmem_cache_create("xfs_btree_cur",
 			xfs_btree_cur_sizeof(XFS_BTREE_CUR_ZONE_MAXLEVELS),
 			0, 0, NULL);