While trying to add a disk to md raid0 with the new device by using the command "mdadm /dev/md101 --add /dev/sdd"  it throws the  error "add new device failed" but this command creates the raid signature on the newly added disk.

We can reproduce the issue with the below steps:

~~~

[root@localhost ~]# cat /etc/redhat-release 
Red Hat Enterprise Linux release 9.2 (Plow)

[root@localhost ~]# uname -r
5.14.0-427.16.1.el9_4.x86_64

[root@localhost ~]# rpm -qa |grep -i mdadm
mdadm-4.2-8.el9.x86_64

[root@localhost ~]# lsblk
NAME          MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
sda             8:0    0 102.4M  0 disk 
sdb             8:16   0 102.4M  0 disk 
sdc             8:32   0 102.4M  0 disk 
sdd             8:48   0 102.4M  0 disk 
sde             8:64   0 102.4M  0 disk 
sr0            11:0    1  1024M  0 rom  
vda           252:0    0    10G  0 disk 
├─vda1        252:1    0     1G  0 part /boot
└─vda2        252:2    0     9G  0 part 
  ├─rhel-root 253:0    0     8G  0 lvm  /
  └─rhel-swap 253:1    0     1G  0 lvm  [SWAP]

===> Created the RAID0 with the 3 devices.
 
[root@localhost ~]# mdadm -create  /dev/md101  -level=raid0 --raid-devices=3  /dev/sda /dev/sdb /dev/sdc
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md101 started.

[root@localhost ~]# cat /proc/mdstat 
Personalities : [raid6] [raid5] [raid4] [raid0] 
md101 : active raid0 sdc[2] sdb[1] sda[0]
      307200 blocks super 1.2 512k chunks
      
unused devices: <none>

--> Array created and it's in active state.

[root@localhost ~]# mdadm -D /dev/md101 
/dev/md101:
           Version : 1.2
     Creation Time : Mon Jun 10 19:56:47 2024
        Raid Level : raid0
        Array Size : 307200 (300.00 MiB 314.57 MB)
      Raid Devices : 3
     Total Devices : 3
       Persistence : Superblock is persistent

       Update Time : Mon Jun 10 19:56:47 2024
             State : clean 
    Active Devices : 3
   Working Devices : 3
    Failed Devices : 0
     Spare Devices : 0

            Layout : unknown
        Chunk Size : 512K

Consistency Policy : none

              Name : localhost.localdomain:101  (local to host localhost.localdomain)
              UUID : 0382685c:fdb8335a:42c94258:77730569
            Events : 0

    Number   Major   Minor   RaidDevice State
       0       8        0        0      active sync   /dev/sda
       1       8       16        1      active sync   /dev/sdb
       2       8       32        2      active sync   /dev/sdc

--> When I tried to add the device to the md101 it's throwing the below error but leaving the md raid signature on the disk.

[root@localhost ~]# mdadm /dev/md101 --add /dev/sdd
mdadm: add new device failed for /dev/sdd as 3: Invalid argument

[root@localhost ~]# blkid |grep -i raid
/dev/sdd: UUID="0382685c-fdb8-335a-42c9-425877730569" UUID_SUB="f682dc02-62af-d480-b1ed-da15bd603cb8" LABEL="localhost.localdomain:101" TYPE="linux_raid_member"
/dev/sdb: UUID="0382685c-fdb8-335a-42c9-425877730569" UUID_SUB="e7d92098-5cbe-8d3c-b968-c0e119fabf89" LABEL="localhost.localdomain:101" TYPE="linux_raid_member"
/dev/sdc: UUID="0382685c-fdb8-335a-42c9-425877730569" UUID_SUB="29dfdff0-8609-5702-e0fd-f101f22c9b29" LABEL="localhost.localdomain:101" TYPE="linux_raid_member"
/dev/sda: UUID="0382685c-fdb8-335a-42c9-425877730569" UUID_SUB="c71818a0-0e25-1a15-8e89-6a719cbfd38c" LABEL="localhost.localdomain:101" TYPE="linux_raid_member"

EXPECTATION:

If a command is failing then it should not write the raid signature on the disk or with the failed state it should clear the command references.

NOTE: Issue is reproducible on RHEL 8, RHEL9