root@debian8:~# cat /proc/mounts | grep ext4fs
/dev/mapper/vg00-ext4fs /mnt/ext4fs ext4 rw,relatime,data=ordered 0 0
root@debian8:~# ls -l /dev/vg00/ext4fs 
lrwxrwxrwx 1 root root 7 Jul  8 10:24 /dev/vg00/ext4fs -> ../dm-0
root@debian8:~# cat /proc/fs/ext4/dm-0/options 
rw
delalloc
barrier
user_xattr
acl
resuid=0
resgid=0
errors=continue
commit=5
min_batch_time=0
max_batch_time=15000
stripe=0
data=ordered
inode_readahead_blks=32
init_itable=10
max_dir_size_kb=0
root@debian8:~#