Sample go code to monitor changes to mounts on linux using epoll

mountpoll.go

package main

import (
	"log"
	"os"
	"syscall"
)

const mpath = "/proc/mounts"

func main() {
	epfd, err := syscall.EpollCreate(1)
	if err != nil {
		log.Fatalf("Failed to create epoll: %v", err)
	}

	f, err := os.Open(mpath)
	if err != nil {
		log.Fatalf("Failed to open mounts file: %v", err)
	}

	err = syscall.EpollCtl(epfd, syscall.EPOLL_CTL_ADD, int(f.Fd()), &syscall.EpollEvent{
		// Events generated when the mounts are changed are EPOLLPRI and EPOLLERR.
		// Read http://lkml.iu.edu/hypermail/linux/kernel/1012.1/02246.html
		Events: syscall.EPOLLPRI | syscall.EPOLLERR,
		Fd:     int32(f.Fd()),
	})
	if err != nil {
		log.Fatalf("Failed to update epoll interest list: %v", err)
	}
	events := make([]syscall.EpollEvent, 2)
	for true {
		log.Println("Waiting for events...")

		// Wait for events on the mounts file indefinitely
		n, err := syscall.EpollWait(epfd, events, -1)
		if err != nil {
			log.Fatalf("Erro while waiting for events: %v", err)
		}
		processEvents(events, n)
	}

}

func processEvents(events []syscall.EpollEvent, count int) {
	log.Printf("Processing %d events...\n", count)
	for i := 0; i < count; i++ {
		log.Println(events[i])
		ev := events[i].Events
		if (ev & syscall.EPOLLPRI) > 0 {
			log.Println("EPOLLPRI ")
		}
		if (ev & syscall.EPOLLIN) > 0 {
			log.Println("EPOLLIN ")
		}
		if (ev & syscall.EPOLLERR) > 0 {
			log.Println("EPOLLERR ")
		}
	}
}