mount: add note about "already mounted" behavior

Addresses: https://github.com/karelzak/util-linux/issues/448
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/sys-utils/mount.8 b/sys-utils/mount.8
index c5f7c1408bf10e18f689af0dbb94b961503414ab..f492f7f252a22c7962cc18a77d053134f846f0e1 100644 (file)
--- a/sys-utils/mount.8
+++ b/sys-utils/mount.8
@@ -113,6 +113,13 @@ options to avoid ambivalent interpretation of the given argument.  For example:
 .sp
 .RE
 
+The same filesystem may be mounted more than once, and in some cases (e.g.
+network filesystems) the same filesystem maybe be mounted on the same
+mountpoint more times. The mount command does not implement any policy to
+control this behavior. All behavior is controlled by kernel and it is usually
+specific to filesystem driver. The exception is \fB\-\-all\fR, in this case
+already mounted filesystems are ignored.
+
 .SS Listing the mounts
 The listing mode is maintained for backward compatibility only.