how to make read write permission

i ,
this is ganesh . i tried to change partition permission but i cant able to change it . i have four partition in my cf card . all the partitions are read write permissions .i have to change some partitions are read only but i can’t able to do it …please give solutions …

i was following this way but not used:

1)chmod -R 444 /partition/path/name
3)umask 277
3)change umask inside /etc/profile

please give the solutions…

thanks and regards,
ganesan p

Change your Mount command to the partition to mount as read only by adding a -r option.