main: add "-o" option to enable "suid" and "dev"

Device files and suid binaries are often not needed when running
gocryptfs as root. As they are potentially dangerous, let the
user enable them explicitely via the new "-o" option instead of
always enabling them when running as root.

1 files changed, 9 insertions, 0 deletions

diff --git a/Documentation/MANPAGE.md b/Documentation/MANPAGE.md
index 11d903d..66e8606 100644
--- a/Documentation/MANPAGE.md
+++ b/Documentation/MANPAGE.md
@@ -85,6 +85,15 @@ continue be printed to stdout and stderr.
 :	Send USR1 to the specified process after successful mount. This is
 used internally for daemonization.
 
+**-o**
+: Pass additonal mount options to the kernel (comma-separated list).
+FUSE filesystems are mounted with "nodev,nosuid" by default. If gocryptfs
+runs as root, you can enable device files by passing the opposite mount option,
+"dev", and if you want to enable suid-binaries, pass "suid".
+"ro" (equivalent to passing the "-ro" option) and "noexec" may also be
+interesting. For a complete liste see the section
+`FILESYSTEM-INDEPENDENT MOUNT OPTIONS` in mount(8).
+
 **-openssl bool**
 :	Use OpenSSL instead of built-in Go crypto (default "auto"). Using
 built-in crypto is 4x slower unless your CPU has AES instructions and