diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index b42a52bfa1e9..4f665646ba7d 100644
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -1198,6 +1198,22 @@ typedef struct xfs_dqblk {
 
 #define XFS_DQUOT_CRC_OFF	offsetof(struct xfs_dqblk, dd_crc)
 
+/*
+ * This defines the unit of allocation of dquots.
+ *
+ * Currently, it is just one file system block, and a 4K blk contains 30
+ * (136 * 30 = 4080) dquots. It's probably not worth trying to make
+ * this more dynamic.
+ *
+ * However, if this number is changed, we have to make sure that we don't
+ * implicitly assume that we do allocations in chunks of a single filesystem
+ * block in the dquot/xqm code.
+ *
+ * This is part of the ondisk format because the structure size is not a power
+ * of two, which leaves slack at the end of the disk block.
+ */
+#define XFS_DQUOT_CLUSTER_SIZE_FSB	(xfs_filblks_t)1
+
 /*
  * Remote symlink format and access functions.
  */
diff --git a/fs/xfs/xfs_qm.h b/fs/xfs/xfs_qm.h
index 7b0e771fcbce..2c8ca9df23af 100644
--- a/fs/xfs/xfs_qm.h
+++ b/fs/xfs/xfs_qm.h
@@ -30,17 +30,6 @@ extern struct kmem_zone	*xfs_qm_dqtrxzone;
 	!dqp->q_core.d_rtbcount && \
 	!dqp->q_core.d_icount)
 
-/*
- * This defines the unit of allocation of dquots.
- * Currently, it is just one file system block, and a 4K blk contains 30
- * (136 * 30 = 4080) dquots. It's probably not worth trying to make
- * this more dynamic.
- * XXXsup However, if this number is changed, we have to make sure that we don't
- * implicitly assume that we do allocations in chunks of a single filesystem
- * block in the dquot/xqm code.
- */
-#define XFS_DQUOT_CLUSTER_SIZE_FSB	(xfs_filblks_t)1
-
 /* Defaults for each quota type: time limits, warn limits, usage limits */
 struct xfs_def_quota {
 	time64_t	btimelimit;	/* limit for blks timer */