the filesystem is already mounted.
           This behavior is the default for --all; otherwise, it depends on the
           kernel filesystem driver. Some filesystems may be mounted more than
           once on the same mount point (e.g. tmpfs).

       --options-mode mode
           Controls how to combine options from fstab/mtab with options from
           the command line. mode can be one of ignore, append, prepend or
           replace. For example, append means that options from fstab are
           appended to options from the command line. The default value is
           prepend — it means command line options are evaluated after fstab
           options. Note that the last option wins if there are conflicting
           ones.

       --options-source source
           Source of default options. source is a comma-separated list of
           fstab, mtab and disable. disable disables fstab and mtab and enables
           --options-source-force. The default value is fstab,mtab.

       --options-source-force
           Use options from fstab/mtab even if both device and dir are
           specified.

       -R, --rbind
           Remount a subtree and all possible submounts somewhere else (so that
           its contents are available in both places). See above, the
           subsection Bind mount operation.

       -r, --read-only
           Mount the filesystem read-only. A synonym is -o ro.

           Note that, depending on the filesystem type, state and kernel
           behavior, the system may still write to the device. For example,
           ext3 and ext4 will replay the journal if the filesystem is dirty. To
           prevent this kind of write access, you may want to mount an ext3 or
           ext4 filesystem with the ro,noload mount options or set the block
           device itself to read-only mode, see the blockdev(8) command.

       -s
           Tolerate sloppy mount options rather than failing. This will ignore
           mount options not supported by a filesystem type. Not all
           filesystems support this option. Currently it’s supported by the
           mount.nfs mount helper only.

       --source device
           If only one argument for the mount command is given, then the
           argument might be interpreted as the target (mountpoint) or source
           (device). This option allows you to explicitly define that the
           argument is the mount source.

       --target directory
           If only one argument for the mount command is given, then the
           argument might be interpreted as the target (mountpoint) or source
           (device). This option allows you to explicitly define that the
           argument is the mount target.

       --target-prefix directory
           Prepend the specified directory to all mount targets. This option
           can be used to follow fstab, but mount operations are done in
           another place, for example:

           mount --all --target-prefix /chroot -o X-mount.mkdir

           mounts all from system fstab to /chroot, all missing mountpoint are
           created (due to X-mount.mkdir). See also --fstab to use an
           alternative fstab.

       -T, --fstab path
           Specifies an alternative fstab file. If path is a directory, then
           the files in the directory are sorted by strverscmp(3); files that
           start with "." or without an .fstab extension are ignored. The
           option can be specified more than once. This option is mostly
           designed for initramfs or chroot scripts where additional
           configuration is specified beyond standard system configuration.

           Note that mount does not pass the option --fstab to the
           /sbin/mount.type helpers, meaning that the alternative fstab files
           will be invisible for the helpers. This is no problem for normal
           mounts, but user (non-root) mounts always require fstab to verify
           the user’s