diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index aeffeaaac0ec406e543730eb608de1eb3ebc40fb..f1026e86dabc9a00ead716785a3acb5c19ee8e10 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -3224,12 +3224,24 @@ xfs_bmap_extsize_align(
 		align_alen += temp;
 		align_off -= temp;
 	}
+
+	/* Same adjustment for the end of the requested area. */
+	temp = (align_alen % extsz);
+	if (temp)
+		align_alen += extsz - temp;
+
 	/*
-	 * Same adjustment for the end of the requested area.
+	 * For large extent hint sizes, the aligned extent might be larger than
+	 * MAXEXTLEN. In that case, reduce the size by an extsz so that it pulls
+	 * the length back under MAXEXTLEN. The outer allocation loops handle
+	 * short allocation just fine, so it is safe to do this. We only want to
+	 * do it when we are forced to, though, because it means more allocation
+	 * operations are required.
 	 */
-	if ((temp = (align_alen % extsz))) {
-		align_alen += extsz - temp;
-	}
+	while (align_alen > MAXEXTLEN)
+		align_alen -= extsz;
+	ASSERT(align_alen <= MAXEXTLEN);
+
 	/*
 	 * If the previous block overlaps with this proposed allocation
 	 * then move the start forward without adjusting the length.
@@ -3318,7 +3330,9 @@ xfs_bmap_extsize_align(
 			return -EINVAL;
 	} else {
 		ASSERT(orig_off >= align_off);
-		ASSERT(orig_end <= align_off + align_alen);
+		/* see MAXEXTLEN handling above */
+		ASSERT(orig_end <= align_off + align_alen ||
+		       align_alen + extsz > MAXEXTLEN);
 	}
 
 #ifdef DEBUG
@@ -4099,13 +4113,6 @@ xfs_bmapi_reserve_delalloc(
 	/* Figure out the extent size, adjust alen */
 	extsz = xfs_get_extsz_hint(ip);
 	if (extsz) {
-		/*
-		 * Make sure we don't exceed a single extent length when we
-		 * align the extent by reducing length we are going to
-		 * allocate by the maximum amount extent size aligment may
-		 * require.
-		 */
-		alen = XFS_FILBLKS_MIN(len, MAXEXTLEN - (2 * extsz - 1));
 		error = xfs_bmap_extsize_align(mp, got, prev, extsz, rt, eof,
 					       1, 0, &aoff, &alen);
 		ASSERT(!error);