Re: [PATCH] debugfs show actual source in /proc/mounts

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Tue, Aug 13, 2024 at 02:18:07PM -0500, Eric Sandeen wrote:
> On 8/13/24 4:54 AM, Greg Kroah-Hartman wrote:
> > On Sat, Aug 10, 2024 at 01:25:27PM -0600, Marc Aurèle La France wrote:
> >> After its conversion to the new mount API, debugfs displays "none" in
> >> /proc/mounts instead of the actual source.  Fix this by recognising its
> >> "source" mount option.
> >>
> >> Signed-off-by: Marc Aurèle La France <tsi@tuyoix.net>
> >> Fixes: a20971c18752 ("vfs: Convert debugfs to use the new mount API")
> >> Cc: stable@vger.kernel.org # 6.10.x: 9f111059e725: fs_parse: add uid & gid option option parsing helpers
> >> Cc: stable@vger.kernel.org # 6.10.x: 49abee5991e1: debugfs: Convert to new uid/gid option parsing helpers
> > 
> > As this came from a fs tree, I'll let the vfs maintainer take it if they
> > think it is ok as I know nothing about the fs_parse stuff at the moment,
> > sorry.
> 
> Hm, I guess this is OK, though it seems a little unexpected for debugfs
> to have to parse the trivial internal "source" option.
> 
> This actually worked OK until
> 
> 0c07c273a5fe debugfs: continue to ignore unknown mount options
> 
> but after that commit, debugfs claims to parse "source" successfully even
> though it has not. So really, it Fixes: that commit, not the original
> conversion.
> 
> I'm not sure of a better approach offhand, but maybe a comment about why
> Opt_source exists in debugfs would help future readers?

Why is debugfs unique here?  Why does it need to do something that
nothing else needs to do (like sysfs or tracefs or anything else...)

thanks,

greg k-h