Re: [PATCH 02/10] xfs: set lv_bytes in xlog_write_one_vec

[Christoph Hellwig <hch@lst.de>]

On Fri, Oct 31, 2025 at 05:04:09PM -0700, Darrick J. Wong wrote:
> > diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
> > index ed83a0e3578e..382c55f4d8d2 100644
> > --- a/fs/xfs/xfs_log.c
> > +++ b/fs/xfs/xfs_log.c
> > @@ -858,14 +858,15 @@ xlog_write_one_vec(
> >  	struct xfs_log_vec	lv = {
> >  		.lv_niovecs	= 1,
> >  		.lv_iovecp	= reg,
> > +		.lv_bytes	= reg->i_len,
> 
> I'm surprised that nothing's noticed the zero lv_bytes, but I guess
> unmount and commit record writes have always wanted a full write anyway?
> 
> Question: if lv_bytes is no longer zero, can this fall into the
> xlog_write_partial branch?

The unmount format is smaller than an opheader, so we won't split it
because of that, but unless I'm misreading things it could fix a bug
where we'd not get a new iclog when needed for it otherwise?

The commit record is just an an opheader without any payload, so there
is no way to even split it in theory.

>