Centos7 start error: Entering emergency mode.Exit the shell to continue

input journalctl

journalctl

Then keep pressing the space bar to jump to the last page to see the red part in the figure below. Check the content in brackets behind XFS to see whether it is sda2 or sda3

My name is sda2

Input: XFS_ repair -v -L /dev/sda2

xfs_repair -v -L /dev/sda2

After the repair, enter reboot to restart

reboot