On Fri, Oct 06, 2017 at 01:09:42PM +1100, Dave Chinner wrote: > On Thu, Oct 05, 2017 at 12:16:19PM -0400, J. Bruce Fields wrote: > > This kind of restriction sounds more like a permanent feature of the > > filesystem--something you'd set at mkfs time. > > > > We already have filesystems with these kinds of restrictions, don't we? > > In general, no. Filename storage typically defined in the > filesystem on-disk formats as an opaque string of bytes - the > filesystem has no business parsing them to determine validity of the > bytes. Think encrypted filenames and the like - control characters > in the on-disk format are most definitely necessary and therefore > must be legal. Umm. But filenames still can't have / or \0 in them, so your encryption already has to avoid at least two special characters. I agree with your main point though; there is no advantage to doing this in each individual filesystem.
