diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 26cf811f3d96..b6f85e488d5c 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -765,6 +765,11 @@ xfs_iomap_write_unwritten(
 	 */
 	resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;
 
+	/* Attach dquots so that bmbt splits are accounted correctly. */
+	error = xfs_qm_dqattach(ip);
+	if (error)
+		return error;
+
 	do {
 		/*
 		 * Set up a transaction to convert the range of extents
@@ -783,6 +788,11 @@ xfs_iomap_write_unwritten(
 		xfs_ilock(ip, XFS_ILOCK_EXCL);
 		xfs_trans_ijoin(tp, ip, 0);
 
+		error = xfs_trans_reserve_quota_nblks(tp, ip, resblks, 0,
+				XFS_QMOPT_RES_REGBLKS);
+		if (error)
+			goto error_on_bmapi_transaction;
+
 		/*
 		 * Modify the unwritten extent state of the buffer.
 		 */