doc: clarify superuser note for ceph-fuse

Signed-off-by: Patrick Donnelly <pdonnell@redhat.com>
(cherry picked from commit d100de9c9ce884beee6e9551b2b221c686b775b5)

diff --git a/doc/cephfs/mount-using-fuse.rst b/doc/cephfs/mount-using-fuse.rst
index f3ac054c9be15d8a55c22e01e04f6000dd53ffa0..31ef9e3472b5f322afb6811905079d624900d6ec 100644 (file)
--- a/doc/cephfs/mount-using-fuse.rst
+++ b/doc/cephfs/mount-using-fuse.rst
@@ -12,8 +12,11 @@ Prerequisites
 Go through the prerequisites required by both, kernel as well as FUSE mounts,
 in `Mount CephFS: Prerequisites`_ page.
 
-.. note:: Mounting CephFS using FUSE requires superuser privileges to trim dentries
-   by issuing a remount of itself.
+.. note:: Mounting CephFS using FUSE requires superuser privileges (sudo/root).
+          The libfuse interface does not provide a mechanism to trim cache entries in the
+          kernel so a remount (``mount(2)``) system call is required to force the kernel
+          to drop the cached metadata. ``ceph-fuse`` issues these remount system calls
+          periodically in response to cache pressure in the MDS or due to metadata cache revocations.
 
 Synopsis
 ========