[PATCH 1/2] md: raid5 return new layout in mdstat while reshaping

[PATCH 1/2] md: raid5 return new layout in mdstat while reshaping

[Trela, Maciej]

From: Maciej Trela <maciej.trela@intel.com>

While reshaping, report mdstat algorithm according to the new_layout.

Signed-off-by: Maciej Trela <maciej.trela@intel.com>
---
 drivers/md/raid5.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 4d85632..b7c6561 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5256,8 +5256,12 @@ static void status(struct seq_file *seq, mddev_t *mddev)
 	raid5_conf_t *conf = mddev->private;
 	int i;
 
-	seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level,
-		mddev->chunk_sectors / 2, mddev->layout);
+	seq_printf(seq, " level %d, %dk chunk,", mddev->level,
+		mddev->chunk_sectors / 2);
+	if (mddev->reshape_position != MaxSector)
+		seq_printf(seq, " algorithm %d", mddev->new_layout);
+	else
+		seq_printf(seq, " algorithm %d", mddev->layout);
 	seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
 	for (i = 0; i < conf->raid_disks; i++)
 		seq_printf (seq, "%s",

Re: [PATCH 1/2] md: raid5 return new layout in mdstat while reshaping

[Dan Williams]

On Wed, Jul 21, 2010 at 4:03 AM, Trela, Maciej <Maciej.Trela@intel.com> wrote:
> From: Maciej Trela <maciej.trela@intel.com>
>
> While reshaping, report mdstat algorithm according to the new_layout.

It's not immediately clear to me why this is needed?  The md/layout
attribute in sysfs shows the new_layout during reshape if userspace
forgets what it changed (should also be recorded in the metadata).  If
it is needed then spell that out in the commit message.

--
Dan

RE: [PATCH 1/2] md: raid5 return new layout in mdstat while reshaping

[Trela, Maciej]

> -----Original Message-----
> From: dan.j.williams@gmail.com [mailto:dan.j.williams@gmail.com] On
> Behalf Of Dan Williams
> Sent: Thursday, July 22, 2010 2:59 AM
> To: Trela, Maciej
> Cc: Neil Brown; Kwolek, Adam; linux-raid@vger.kernel.org
> Subject: Re: [PATCH 1/2] md: raid5 return new layout in mdstat while
> reshaping
> 
> On Wed, Jul 21, 2010 at 4:03 AM, Trela, Maciej <Maciej.Trela@intel.com>
> wrote:
> > From: Maciej Trela <maciej.trela@intel.com>
> >
> > While reshaping, report mdstat algorithm according to the new_layout.
> 
> It's not immediately clear to me why this is needed?  The md/layout
> attribute in sysfs shows the new_layout during reshape if userspace
> forgets what it changed (should also be recorded in the metadata).  If
> it is needed then spell that out in the commit message.
> 

Yes, you are right.
We can definitely read the new layout from sysfs.
Thanks.