On 2023/5/9 07:49, Guilherme G. Piccoli wrote:
On 08/05/2023 20:18, Qu Wenruo wrote:
[...]
I see that we seem to have 3 proposals here:
(a) The compat_ro flag from Qu;
(b) Your idea (that requires some clarification for my fully
understanding - thanks in advance!);
(c) Renaming the mount option "virtual_fsid" to "nouuid" to keep
filesystem consistency, like XFS (courtesy of Dave Chinner) - please
correct me here if I misunderstood you Dave =)
To me, (a) and (c) don't conflict at all.
We can allow "nouuid" only to work with SINGLE_DEV compat_ro.
That compat_ro flags is more like a better guarantee that the fs will
never have more disks.
As even with SINGLE_DEV compat_ro flags, we may still want some checks
to prevent the same fs being RW mounted at different instances, which
can cause other problems, thus dedicated "nouuid" may still be needed.
Thanks,
Qu
Hey Qu, I confess now I'm a bit confused heh
The whole idea of (a) was to *not* use a mount option, right?! Per my
understanding of your objections in this thread, you're not into a mount
option for this same-fsid feature (based on a bad previous experience,
as you explained).
My bad, I initially thought there would be some extra checks inside VFS
layer rejecting the same fs.
But after checking the xfs code, it looks like it's handling the nouuid
internally.
Thus no need for nouuid mount option if we go compat_ro.
Although I would still like a nouuid mount option, which is only valid
if the fs has the compat_ro flags, to provide a generic behavior just
like XFS.
Thanks,
Qu
If we're keeping the "nouuid" mount option, why we'd require the
compat_ro flag? Or vice-versa: having the compat_ro flag, why we'd need
the mount option? >
Thanks in advance for clarifications,
Guilherme
