Re: [PATCH 2/5] fstests: add mmap page boundary tests

[Luis Chamberlain <mcgrof@kernel.org>]

On Wed, Jun 12, 2024 at 04:06:34PM +0800, Zorro Lang wrote:
> On Mon, Jun 10, 2024 at 08:01:59PM -0700, Luis Chamberlain wrote:
> > +mwrite()
> > +{
> > +       local file=$1
> > +       local offset=$2
> > +       local length=$3
> > +       local map_len=${4:-$(_round_up_to_page_boundary $(_get_filesize $file)) }
> > +
> > +       # Some callers expect xfs_io to crash with SIGBUS due to the mread,
> > +       # causing the shell to print "Bus error" to stderr.  To allow this
> > +       # message to be redirected, execute xfs_io in a new shell instance.
> > +       # However, for this to work reliably, we also need to prevent the new
> > +       # shell instance from optimizing out the fork and directly exec'ing
> > +       # xfs_io.  The easiest way to do that is to append 'true' to the
> > +       # commands, so that xfs_io is no longer the last command the shell sees.
> > +       bash -c "trap '' SIGBUS; ulimit -c 0; \
> > +		$XFS_IO_PROG $file \
> > +               -c 'mmap -w 0 $map_len' \
> > +               -c 'mwrite $offset $length'; \
> > +	       true"
> > +}
> 
> As you've moved the _mread to common/rc, why not do the same for this mwrite?

I didn't move it as this mwrite() is only used by one test. Let me know
if you want me to move it.

  Luis