Re: [PATCH 2/2] xfs/21[67]: fix mkfs log concurrency detection

On Tue, Jun 30, 2026 at 01:53:38AM +0800, Zorro Lang wrote:
> On Thu, Jun 25, 2026 at 09:51:17AM -0700, Darrick J. Wong wrote:
> > From: Darrick J. Wong <[email protected]>
> > 
> > Both of these tests use _scratch_mkfs_xfs_supports_concurrency to detect
> > if they should be adding -lconcurrency=0 to the mkfs options that are
> > used to format a loop device.
> > 
> > However, this doesn't work in practice because of three factors: 1) the
> > scratch device could have an external log set up; 2) the loop device
> > does /not/ have an external log device; and 3) -lconcurrency isn't
> > compatible with -llogdev.
> > 
> > Fix this by creating a more general mkfs option detection helper and use
> > that once we have the loop device set up.
> > 
> > Cc: <[email protected]> # v2026.05.17
> > Fixes: ffc8bad17e5b2f ("xfs/21{6,7} Use default -l concurrency=0 on mkfs.xfs that supports it")
> > Signed-off-by: "Darrick J. Wong" <[email protected]>
> > ---
> >  common/xfs    |    6 ++++++
> >  tests/xfs/216 |    9 ++++-----
> >  tests/xfs/217 |    9 ++++-----
> >  3 files changed, 14 insertions(+), 10 deletions(-)
> > 
> > 
> > diff --git a/common/xfs b/common/xfs
> > index 88299acdd086be..81add2086866c8 100644
> > --- a/common/xfs
> > +++ b/common/xfs
> > @@ -64,6 +64,12 @@ _scratch_mkfs_xfs_opts()
> >  	echo "$MKFS_XFS_PROG $SCRATCH_OPTIONS $mkfs_opts"
> >  }
> >  
> > +# Figure out if the supplied mkfs.xfs options are supported.  A device or file
> > +# path must be specified as one of the options, though it will not be written.
> > +_mkfs_xfs_supported()
> > +{
> > +	$MKFS_XFS_PROG -f -N "$@"
> > +}
> >  
> >  _scratch_mkfs_xfs_supported()
> >  {
> > diff --git a/tests/xfs/216 b/tests/xfs/216
> > index 1749647c11f716..48657242e65daf 100755
> > --- a/tests/xfs/216
> > +++ b/tests/xfs/216
> > @@ -22,11 +22,6 @@ _cleanup()
> >  
> >  _require_scratch
> >  _scratch_mkfs_xfs >/dev/null 2>&1
> > -if _scratch_mkfs_xfs_supports_concurrency -l >> $seqres.full 2>&1; then
> > -	loop_mkfs_opts="-l concurrency=0"
> > -else
> > -	loop_mkfs_opts=""
> > -fi
> >  _scratch_mount
> >  
> >  _require_loop
> > @@ -76,6 +71,10 @@ mkdir $LOOP_MNT
> >  
> >  loop_dev=$(_create_loop_device $LOOP_IMG)
> >  
> > +if _mkfs_xfs_supported $loop_mkfs_opts -l concurrency=0 $loop_dev &>> $seqres.full; then
> > +	loop_mkfs_opts="$loop_mkfs_opts -l concurrency=0"
> 
> Hi Darrick,
> 
> This patch conflicts with Christoph's patch:
> https://lore.kernel.org/fstests/[email protected]/

Oh, sorry I reviewed this patch at first, then found your later discussion,
so I should do this:
  https://lore.kernel.org/fstests/[email protected]/T/#ma0ead04f569bcc81595ca729744f1466838876fc
right?

> 
> I've merged that patch into patches-in-queue branch, if you don't have
> objections to that change, could you rebase on latest patches-in-queue
> and send this patch again with Christoph's RVB :)
> 
> Thanks,
> Zorro
> 
> > +fi
> > +
> >  # walk over standard sizes (up to 256GB)
> >  _do_mkfs 1 2 4 8 16 32 64 128 256
> >  
> > diff --git a/tests/xfs/217 b/tests/xfs/217
> > index 23aae842d1fb61..34ac8dae8ef43f 100755
> > --- a/tests/xfs/217
> > +++ b/tests/xfs/217
> > @@ -21,11 +21,6 @@ _cleanup()
> >  
> >  _require_scratch
> >  _scratch_mkfs_xfs >/dev/null 2>&1
> > -if _scratch_mkfs_xfs_supports_concurrency -l >> $seqres.full 2>&1; then
> > -	loop_mkfs_opts="-l concurrency=0 -d concurrency=0"
> > -else
> > -	loop_mkfs_opts=""
> > -fi
> >  _scratch_mount
> >  # 16T mkfs requires a bit over 2G free
> >  _require_fs_space $SCRATCH_MNT 2202000
> > @@ -63,6 +58,10 @@ fi
> >  
> >  loop_dev=$(_create_loop_device $LOOP_IMG)
> >  
> > +if _mkfs_xfs_supported $loop_mkfs_opts -l concurrency=0 -d concurrency=0 $loop_dev &>> $seqres.full; then
> > +	loop_mkfs_opts="$loop_mkfs_opts -l concurrency=0 -d concurrency=0"
> > +fi
> > +
> >  #
> >  # walk over "new" sizes supported by recent xfsprogs.
> >  # Note that the last test is for 16TB-1GB as 32bit platforms only support
> > 
>