1.Fix file system
Go to single user/safe mode on boot and try following commands:-
$ fsck_hfs -fyr /dev/disk0s2
or
$ fsck_hfs -fyr /dev/disk0s2
Apply these commands to other disk also, /dev/disk0s1, /dev/disk0s3, /dev/disk0s4 etc depending upon your partitions on disk.
Go to single user/safe mode on boot and try following commands:-
$ fsck_hfs -fyr /dev/disk0s2
or
$ fsck_hfs -fyr /dev/disk0s2
Apply these commands to other disk also, /dev/disk0s1, /dev/disk0s3, /dev/disk0s4 etc depending upon your partitions on disk.