On Tue, Nov 15, 2016 at 05:18:25PM +0100, Thomas Schmitt wrote: > David Wright wrote: > > That umask looks odd. > > Using a thing named "umask" to "Set the file permission on the filesystem" > is odd. No further speculation but only experiments would give clarity.
It's how fat/vfat mounts work in Linux. The file system has no internal owners, groups or permissions, so the kernel simply assigns them. By default, all files on a vfat mount show up as root:root 666 and all directories as root:root 777 as modified by the umask of the mounting process. So if you've got a umask of 022 when you mount, then it's 644 and 755 respectively. Explicitly specifying a umask in the fat/vfat mount options overrides that. See mount(8) for details.
