reverting to read-only mode

How to revert sd-card in read-only mode as before after making settings, I mean what is opposite command to this?:
mount -o remount,rw /flash

Quote from HiassofT

mount -o remount,ro /flash

And how to check that it's read only?

Here is what output after "mount -o remount,ro /flash" command:

LibreELEC:~ # mount

devtmpfs on /dev type devtmpfs (rw,relatime,size=376256k,nr_inodes=94064,mode=755)

proc on /proc type proc (rw,relatime)

sysfs on /sys type sysfs (rw,relatime)

/dev/mmcblk0p1 on /flash type vfat (ro,noatime,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,errors=remount-ro)

/dev/loop0 on / type squashfs (ro,relatime)

/dev/mmcblk0p2 on /storage type ext4 (rw,noatime)

tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)

devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)

tmpfs on /run type tmpfs (rw,nosuid,nodev,mode=755)

tmpfs on /sys/fs/cgroup type tmpfs (ro,nosuid,nodev,noexec,mode=755)

cgroup2 on /sys/fs/cgroup/unified type cgroup2 (rw,nosuid,nodev,noexec,relatime,nsdelegate)

cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,name=systemd)

bpf on /sys/fs/bpf type bpf (rw,nosuid,nodev,noexec,relatime,mode=700)

cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)

cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpu,cpuacct)

cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)

cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset)

cgroup on /sys/fs/cgroup/memory type cgroup (rw,nosuid,nodev,noexec,relatime,memory)

cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)

mqueue on /dev/mqueue type mqueue (rw,nosuid,nodev,noexec,relatime)

debugfs on /sys/kernel/debug type debugfs (rw,nosuid,nodev,noexec,relatime)

tmpfs on /var type tmpfs (rw,relatime)

configfs on /sys/kernel/config type configfs (rw,nosuid,nodev,noexec,relatime)

tmpfs on /tmp type tmpfs (rw,nosuid,nodev)

LibreELEC:~ #