MSDOS Filesystem question related to "read-only" files
cem at freebsd.org
Mon Nov 20 18:55:02 UTC 2017
In fact, msdosfs in FreeBSD should set the FAT READONLY attribute
under two conditions:
1. The owner chmod's the file non-writeable (chmod u-w) (what you've
described, I think). Or,
2. The super user or otherwise privileged user sets the "readonly"
flag on the file via chflags(1).
How have you determined that chmod u-w does nothing? What version of
FreeBSD are you using?
On Mon, Nov 20, 2017 at 7:36 AM, Karl Denninger <karl at denninger.net> wrote:
> I'm running into an interesting issue here and wondering if there's a
> way to do this under FreeBSD.
> MSDOS filesystems have a "primitive" permission capability;
> specifically, they can have a "Read-only" attribute on a file. It looks
> like OpenBSD supports this from reading their man pages.
> FreeBSD doesn't appear to. When you mount a msdos filesystem (e.g. a
> USB stick) whoever owns the parent directory where you mount it gives
> you the permissions and "ownership" of files on said filesystem. All
> good so far. But attempting to chmod a file to remove write permission
> "succeeds" (returns success) but does nothing.
> Is this capability simply not present on FreeBSD? I'm interested in
> using it as a means of "flagging" files on a USB stick in an application
> that I do not want to remove if the stick fills (basically, to "protect"
> them from being aged off) and it appears there's no way to do it, other
> than to use something unique in the filename that I would then have to
> pay attention to.
> Karl Denninger
> karl at denninger.net <mailto:karl at denninger.net>
> /The Market Ticker/
> /[S/MIME encrypted email preferred]/
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