I have a raid5 array and need to stop it, but while trying to stop it getting error.

# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] 
md0 : active raid5 sde1[3](F) sdc1[4](F) sdf1[2] sdd1[1]
      2120320 blocks level 5, 32k chunk, algorithm 2 [3/2] [_UU]

unused devices: <none>
# mdadm --stop
mdadm: metadata format 00.90 unknown, ignored.
mdadm: metadata format 00.90 unknown, ignored.
mdadm: No devices given.
# mdadm --stop /dev/md0
mdadm: metadata format 00.90 unknown, ignored.
mdadm: metadata format 00.90 unknown, ignored.
mdadm: fail to stop array /dev/md0: Device or resource busy

and

# lsof | grep md0
md0_raid5  965       root  cwd       DIR        8,1      4096          2 /
md0_raid5  965       root  rtd       DIR        8,1      4096          2 /
md0_raid5  965       root  txt   unknown                                 /proc/965/exe
# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] 
md0 : active raid5 sde1[3](F) sdc1[4](F) sdf1[2] sdd1[1]
      2120320 blocks level 5, 32k chunk, algorithm 2 [3/2] [_UU]
# grep md0 /proc/mdstat
md0 : active raid5 sde1[3](F) sdc1[4](F) sdf1[2] sdd1[1]
# grep md0 /proc/partitions
   9        0    2120320 md0

While booting, md1 is mounted ok but md0 failed for some unknown reason

# dmesg | grep md[0-9]
[    4.399658] raid5: allocated 3179kB for md1
[    4.400432] raid5: raid level 5 set md1 active with 3 out of 3 devices, algorithm 2
[    4.400678] md1: detected capacity change from 0 to 2121793536
[    4.403135]  md1: unknown partition table
[   38.937932] Filesystem "md1": Disabling barriers, trial barrier write failed
[   38.941969] XFS mounting filesystem md1
[   41.058808] Ending clean XFS mount for filesystem: md1
[   46.325684] raid5: allocated 3179kB for md0
[   46.327103] raid5: raid level 5 set md0 active with 2 out of 3 devices, algorithm 2
[   46.330620] md0: detected capacity change from 0 to 2171207680
[   46.335598]  md0: unknown partition table
[   46.410195] md: recovery of RAID array md0
[  117.970104] md: md0: recovery done.
# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] 
md0 : active raid5 sde1[0] sdf1[2] sdd1[1]
      2120320 blocks level 5, 32k chunk, algorithm 2 [3/3] [UUU]

md1 : active raid5 sdc2[0] sdf2[2] sde2[3](S) sdd2[1]
      2072064 blocks level 5, 128k chunk, algorithm 2 [3/3] [UUU]