well with some experiment i found the answer,
I had used mke2fs /dev/mmcblk0p2
command to format the partition. And after that if i mount /dev/mmcblk0p2
on the /media/emmcrfs
mount spits message that it is mounting file system without journal.
when i used mkfs.ext4 /dev/mmcblk0p2
command to format the partition and then mount /dev/mmcblk0p2
i see mount giving message that it is mounting file system with journal. For exact message see below command
# mount -t ext4 /dev/mmcblk0p2 /media/emmcrfs/
[ 3172.107869] EXT4-fs (mmcblk0p2): mounted filesystem with ordered data mode. Opts: (null)
So when i googled it i found that mke2fs
utility refers /etc/mke2fs.conf
file for different options. if mke2fs is not given any argument it takes parameters from [defaults]
from the /etc/mke2fs.conf
and these [defaults]
parameters doesn't have journal option.
When i use command mkfs.ext4
it internally calls mke2fs
with ext4
as parameter and because of which mke2fs
refers parameters for [ext4]
in the /etc/mke2fs.conf
. In my case [ext4]
contains the journaling option so it creates journal.
Hope it helps someone having same question as me :)