After and include kernel v5.4, it adds one feature bit
MD_FEATURE_RAID0_LAYOUT. It must need to specify a layout for raid0 with more
than one zone. But for raid0 with one zone, in fact it also has a defalut
layout.

Now for raid0 with one zone, *unknown* layout can be seen when running mdadm
-D command. It's the reason that mdadm doesn't set MD_FEATURE_RAID0_LAYOUT for
raid0 with one zone. Then in kernel space, super_1_validate sets mddev->layout
to -1 because of no MD_FEATURE_RAID0_LAYOUT. In fact, in raid0 io path, it
uses the default layout. So in fact after/include kernel v5.4, all raid0
device have layout.

Fixes: 329dfc28debb ('Create: add support for RAID0 layouts.')
Signed-off-by: Xiao Ni <redacted>
---
 super1.c | 21 ++-------------------
 1 file changed, 2 insertions(+), 19 deletions(-)

diff --git a/super1.c b/super1.c
index 856b02082662..653a2ea6c0e4 100644
--- a/super1.c
+++ b/super1.c

@@ -1978,26 +1978,10 @@ static int write_init_super1(struct supertype *st)
 	unsigned long long sb_offset;
 	unsigned long long data_offset;
 	long bm_offset;
-	int raid0_need_layout = 0;
 
-	for (di = st->info; di; di = di->next) {
+	for (di = st->info; di; di = di->next)
 		if (di->disk.state & (1 << MD_DISK_JOURNAL))
 			sb->feature_map |= __cpu_to_le32(MD_FEATURE_JOURNAL);
-		if (sb->level == 0 && sb->layout != 0) {
-			struct devinfo *di2 = st->info;
-			unsigned long long s1, s2;
-			s1 = di->dev_size;
-			if (di->data_offset != INVALID_SECTORS)
-				s1 -= di->data_offset;
-			s1 /= __le32_to_cpu(sb->chunksize);
-			s2 = di2->dev_size;
-			if (di2->data_offset != INVALID_SECTORS)
-				s2 -= di2->data_offset;
-			s2 /= __le32_to_cpu(sb->chunksize);
-			if (s1 != s2)
-				raid0_need_layout = 1;
-		}
-	}