Use case: I came across this using # mount -o remount,allow_root /run/user/<uid>/gvfs which I wanted to use to allow a debugging scenario that involves stuff running as both root and under my desktop UID, and not being able to access it all as root turned out inconvenient. Somewhat similar to what's described in bug #531188, but not that exact issue. Actual result: /bin/sh: line 1: gvfsd-fuse: command not found Expected result: The options on the mounted filesystem are updated. A short dig into this shows that gvfsd-fuse is installed as /usr/libexec/gvfsd-fuse (that's the gnome-base/gvfs part), and /sbin/mount.fuse (that's the sys-fs/fuse part, and what the call of /bin/mount results in) is not looking for it there. Looking at an strace, apparently it's looking in: 3169167 newfstatat(AT_FDCWD, "/usr/local/sbin/gvfsd-fuse", 0x7ffc3685e1b0, 0) = -1 ENOENT (No such file or directory) 3169167 newfstatat(AT_FDCWD, "/usr/local/bin/gvfsd-fuse", 0x7ffc3685e1b0, 0) = -1 ENOENT (No such file or directory) 3169167 newfstatat(AT_FDCWD, "/usr/sbin/gvfsd-fuse", 0x7ffc3685e1b0, 0) = -1 ENOENT (No such file or directory) 3169167 newfstatat(AT_FDCWD, "/usr/bin/gvfsd-fuse", 0x7ffc3685e1b0, 0) = -1 ENOENT (No such file or directory) 3169167 newfstatat(AT_FDCWD, "/sbin/gvfsd-fuse", 0x7ffc3685e1b0, 0) = -1 ENOENT (No such file or directory) 3169167 newfstatat(AT_FDCWD, "/bin/gvfsd-fuse", 0x7ffc3685e1b0, 0) = -1 ENOENT (No such file or directory) For testing purposes, I've made a symbolink link of gvfsd-fuse in /usr/sbin pointing to /usr/libexec/gvfsd-fuse. This allows the mount.fuse process to proceed, but does not yield the desired result either: fuse: invalid argument `/run/user/<uid>/gvfs' ... which might excuse that the 'naive' usage of mount -o remount,... /some/gvfs/fuse/fs is not supported, since gvfsd-fuse apparently does not know how to handle a remount request. It does, however, leave the question of how mount options, especially allow_root, can be specified for gvfsd-fuse. The man pages on gvfsd-fuse, gvfs etc. are sorely lacking in that regard.
