.TP
.BR \-a , " \-\-all"
All of the filesystems described in
-.I /etc/mtab
-are unmounted, except the \fIproc\fR filesystem.
+.I /proc/self/mountinfo
+(or in deprecated /etc/mtab)
+are unmounted, except the proc, devfs, devpts, sysfs, rpc_pipefs and nfsd
+filesystems. This list of the filesystems may be replaced by \fB\-\-types\fR
+umount option.
.TP
.BR \-A , " \-\-all\-targets"
Unmount all mountpoints in the current namespace for the specified filesystem.
.B \-\-fake
Causes everything to be done except for the actual system call or umount helper
execution; this 'fakes' unmounting the filesystem. It can be used to remove
-entries from
+entries from the deprecated
.I /etc/mtab
that were unmounted earlier with the
.B \-n
A \fBhelper=\fItype\fR marker in the mtab file will redirect
all unmount requests
to the \fB/sbin/umount.\fItype\fR helper independently of UID.
+.PP
+Note that \fI/etc/mtab\fR is currently deprecated and helper= and another
+userspace mount options are maintained by libmount.
.SH FILES
.TP
.B /etc/mtab
-table of mounted filesystems
+table of mounted filesystems (deprecated and usually replaced by
+symlink to /proc/mounts)
.TP
.B /etc/fstab
table of known filesystems
+.TP
+.B /proc/self/mountinfo
+table of mounted filesystems generated by kernel.
.SH ENVIRONMENT
.IP LIBMOUNT_FSTAB=<path>
overrides the default location of the fstab file (ignored for suid)