Re: [PATCH] generic/050: handle f2fs as nojournal filesystem

[Christoph Hellwig <hch@infradead.org>]

On Fri, Apr 17, 2026 at 12:47:09AM +0800, Zorro Lang wrote:
> > > Therefore, F2FS does not need to write to the device to recover, and
> > > successfully mounts on the read-only block device. Thus, it should be
> > > treated as nojournal in this case.
> > 
> > This looks ok, but I always wonder if we want an opt-in for this
> > "journaling" behavior and/or define it clear in common/.
> 
> _has_traditional_journal ? _has_journal_replay ? :-D

Good question.  We already have _has_metadata_journaling, which is
used in this test and in _require_metadata_journaling.  Unfortunately
no one has bother to describe what behavior it is supposed to guard.

From looking at the _require_metadata_journaling users, it really seems
to be about providing file system consistency after crash.  So maybe
_has_metadata_journaling, should be renamed to this effect?

Now in generic/050 the check patched here is used to select the golden
output.  When I wrote the test originally (I can't even remember that),
it was a XFS-specific test, and Jan then later tested it to add this
_has_metadata_journaling check, which also needed further btrfs
workarounds.  AFAICS it is all about failing the mount if log recovery
is required, but the underlying block device is read-only.  So maybe
name it after that?