Re: [PATCH RFC] vfs: always log mount API fs context messages to dmesg

[Christian Brauner <brauner@kernel.org>]

> * systemd is currently probing with a dummy mount option which will
>   generate noise, see
>   https://github.com/systemd/systemd/blob/main/src/basic/mountpoint-util.c#L759
>   i.e. - 
>   [   10.689256] proc: Unknown parameter 'adefinitelynotexistingmountoption'
>   [   10.801045] tmpfs: Unknown parameter 'adefinitelynotexistingmountoption'
>   [   11.119431] proc: Unknown parameter 'adefinitelynotexistingmountoption'
>   [   11.692032] proc: Unknown parameter 'adefinitelynotexistingmountoption'

Yeah, I remember that they want to know whether a given mount option is
supported or not. That would potentially cause some people to pipe up
complaining about dmesg getting spammed with this if we enable it.

Ok, so right now invalfc() is logged in the fs_context but it isn't
logged in dmesg, right? Would it make sense to massage invalfc() so that
it logs with error into the fs_context but with info into dmesg? This
would avoid spamming dmesg and then we could risk turning this on to see
whether this causes complaints.

You know you could probably test your patch with xfstests to see if this
causes any new test failures because dmesg contains new output. This
doesn't disqualify the patch ofc it might just useful to get an idea how
much noiser we are by doing this.