Ubuntu – /dev/sda2: clean, ***/*** files, ***/*** blocks

My LG gram 15 laptop runs Ubuntu 16.04. When I was running both Makefile and gradle simultaneously, it was getting slower and slower, and finally it froze, so, I rebooted my laptop. Then it started to print only:

/dev/sda2: clean, ***/*** files, ***/*** blocks

Where the *** are large numbers.

CLI mode works well, but I couldn't start the Ubuntu in GUI mode (lightdm, GNOME…)

I searched for a solution. I read almost every relevant answer about this problem, but none of them worked. I tried to reinstall the Nvidia driver, but my computer doesn't have an Nvidia graphics card.

Results of df -h --exclude=tmpfs --exclude=squashfs :

Filesystem | size | Used | Avail | Use% | Mounted on  
udev |0 | 12G | 0% | /dev
/dev/sda2 | 468G | 173G | 272G | 39% | /
/dev/sda1 | 511M | 6.1M | 505M | 2% | /boot/efi

I typed grep EE /var/log/Xorg.0.log suggestion on recovery mode.

$ grep EE /var/log/Xorg.0.log
(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(EE) /dev/dri/card0: failed to set DRM interface version 1.4: Permission denied
(EE) Failed to load module "fbdev" (module does not exist, 0)
(EE) Failed to load module "vesa" (module does not exist, 0)
(EE) Failed to load module "fbdev" (module does not exist, 0)
(EE) Failed to load module "vesa" (module does not exist, 0)
/dev/dri/card0: failed to set DRM interface version 1.4: Permission denied.

After I typed Xorg -configure

List of video drivers:
amdgpu 
ati
intel
nouveau
qxl
radeon
vmware
odsetting
fbdev
vesa
using config file: "/root/xorg.conf.new"
using system config directory "usr/share/X11/xorg.conf.d"
Number of created screens does not match number of detected devices
Configuration failed
Server terminated with error (2). closing log file.

stratx makes below error:

systemd-logind : failed to get session: PID 962 does not belong to any known session
open /dev/dri/card0: No such file or directory
open /dev/dri/card0: No such file or directory
Screen 0 deleted because of no matching config section.
AIGLX: reverting to software rendering

"journalctl -xe -p err -k"

Couldn't get size: 0x8000000000000000e

MODSIGN: Couldn't get UEFI db list

Couldn't get size: 0x8000000000000000e

ip_local_port_range: prefer different parity for start/end values.

Something spring to my mind is that, I forced power off my laptop while It was connected to external monitor via HDMI cable.