What's the purpose of the
/proc/pid/mountinfo file (with pid being numerical process id)?
As far as I can see it reflects contents of the
/proc/mounts file but with added information.
Also the file seems to stay the same for all processes: diff for two randomly chosen processes returns no output (
diff /proc/3833/mountinfo /proc/2349/mountinfo)
Please note that I'm not asking what does it contain. From the definitions on the internet I see that 'This file contains information about mount points.'. I'm asking why is it present in every process directory? What is its purpose there?