All of lore.kernel.org
 help / color / mirror / Atom feed
From: Dave Chinner <david@fromorbit.com>
To: Joe Landman <joe.landman@gmail.com>
Cc: linux-raid <linux-raid@vger.kernel.org>, xfs <xfs@oss.sgi.com>
Subject: Re: interesting MD-xfs bug
Date: Fri, 10 Apr 2015 09:10:35 +1000	[thread overview]
Message-ID: <20150409231035.GI13731@dastard> (raw)
In-Reply-To: <20150409225322.GH13731@dastard>

On Fri, Apr 10, 2015 at 08:53:22AM +1000, Dave Chinner wrote:
> On Thu, Apr 09, 2015 at 06:20:26PM -0400, Joe Landman wrote:
> > 
> > 
> > On 04/09/2015 06:18 PM, Dave Chinner wrote:
> > >On Thu, Apr 09, 2015 at 05:02:33PM -0400, Joe Landman wrote:
> > >>If I build an MD raid0 with a non power of 2 chunk size, it appears
> > >>that I can mkfs.xfs a file system, but it doesn't show up in blkid
> > >>and is not mountable.  Yet, using a power of 2 chunk size, this does
> > >>work correctly.   This is kernel 3.18.9.
> > >>
> > 
> > [...]
> > 
> > >That looks more like a blkid or udev problem. try using blkid -p so
> > >that it doesn't look up the cache but directly probes devices for
> > >the signatures. strace might tell you a bit more, too. And if the
> > >filesystem mounts, then it definitely isn't an XFS problem ;)
> > 
> > Thats the thing, it didn't mount, even when I used the device name
> > directly.
> 
> Ok, that's interesting. Let me see if I can reproduce it locally. If
> you don't hear otherwise, tracing would still be useful. Thanks for
> the bug report, Joe.

No luck - md doesn't allow the device to be activated on 4.0-rc7:

$ sudo mdadm --version
mdadm - v3.3.2 - 21st August 2014
$ uname -a
Linux test4 4.0.0-rc7-dgc+ #882 SMP Fri Apr 10 08:50:52 AEST 2015 x86_64 GNU/Linux
$ sudo wipefs -a /dev/vd[ab]
/dev/vda: 4 bytes were erased at offset 0x00001000 (linux_raid_member): fc 4e 2b a9
/dev/vdb: 4 bytes were erased at offset 0x00001000 (linux_raid_member): fc 4e 2b a9
$ sudo mdadm --create /dev/md20 --level=0 --metadata=1.2 --chunk=1152 --auto=yes --raid-disks=2 /dev/vd[ab]
mdadm: RUN_ARRAY failed: Invalid argument
       Problem may be that chunk size is not a power of 2
$ cat /proc/mdstat
Personalities : [raid1] [raid10] [raid6] [raid5] [raid4] 
unused devices: <none>
$

So I can't actually reproduce what you are seeing because MD doesn't
allow the device to be activated and so mdadm tears it back down.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

WARNING: multiple messages have this Message-ID (diff)
From: Dave Chinner <david@fromorbit.com>
To: Joe Landman <joe.landman@gmail.com>
Cc: linux-raid <linux-raid@vger.kernel.org>, xfs <xfs@oss.sgi.com>
Subject: Re: interesting MD-xfs bug
Date: Fri, 10 Apr 2015 09:10:35 +1000	[thread overview]
Message-ID: <20150409231035.GI13731@dastard> (raw)
In-Reply-To: <20150409225322.GH13731@dastard>

On Fri, Apr 10, 2015 at 08:53:22AM +1000, Dave Chinner wrote:
> On Thu, Apr 09, 2015 at 06:20:26PM -0400, Joe Landman wrote:
> > 
> > 
> > On 04/09/2015 06:18 PM, Dave Chinner wrote:
> > >On Thu, Apr 09, 2015 at 05:02:33PM -0400, Joe Landman wrote:
> > >>If I build an MD raid0 with a non power of 2 chunk size, it appears
> > >>that I can mkfs.xfs a file system, but it doesn't show up in blkid
> > >>and is not mountable.  Yet, using a power of 2 chunk size, this does
> > >>work correctly.   This is kernel 3.18.9.
> > >>
> > 
> > [...]
> > 
> > >That looks more like a blkid or udev problem. try using blkid -p so
> > >that it doesn't look up the cache but directly probes devices for
> > >the signatures. strace might tell you a bit more, too. And if the
> > >filesystem mounts, then it definitely isn't an XFS problem ;)
> > 
> > Thats the thing, it didn't mount, even when I used the device name
> > directly.
> 
> Ok, that's interesting. Let me see if I can reproduce it locally. If
> you don't hear otherwise, tracing would still be useful. Thanks for
> the bug report, Joe.

No luck - md doesn't allow the device to be activated on 4.0-rc7:

$ sudo mdadm --version
mdadm - v3.3.2 - 21st August 2014
$ uname -a
Linux test4 4.0.0-rc7-dgc+ #882 SMP Fri Apr 10 08:50:52 AEST 2015 x86_64 GNU/Linux
$ sudo wipefs -a /dev/vd[ab]
/dev/vda: 4 bytes were erased at offset 0x00001000 (linux_raid_member): fc 4e 2b a9
/dev/vdb: 4 bytes were erased at offset 0x00001000 (linux_raid_member): fc 4e 2b a9
$ sudo mdadm --create /dev/md20 --level=0 --metadata=1.2 --chunk=1152 --auto=yes --raid-disks=2 /dev/vd[ab]
mdadm: RUN_ARRAY failed: Invalid argument
       Problem may be that chunk size is not a power of 2
$ cat /proc/mdstat
Personalities : [raid1] [raid10] [raid6] [raid5] [raid4] 
unused devices: <none>
$

So I can't actually reproduce what you are seeing because MD doesn't
allow the device to be activated and so mdadm tears it back down.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

  reply	other threads:[~2015-04-09 23:10 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-09 21:02 interesting MD-xfs bug Joe Landman
2015-04-09 21:02 ` Joe Landman
2015-04-09 22:18 ` Dave Chinner
2015-04-09 22:18   ` Dave Chinner
2015-04-09 22:20   ` Joe Landman
2015-04-09 22:20     ` Joe Landman
2015-04-09 22:53     ` Dave Chinner
2015-04-09 22:53       ` Dave Chinner
2015-04-09 23:10       ` Dave Chinner [this message]
2015-04-09 23:10         ` Dave Chinner
2015-04-09 23:36         ` NeilBrown
2015-04-09 23:36           ` NeilBrown
2015-04-10  1:31           ` Dave Chinner
2015-04-10  1:31             ` Dave Chinner
2015-04-10  3:22             ` NeilBrown
2015-04-10  3:22               ` NeilBrown
2015-04-10  6:05               ` Dave Chinner
2015-04-10  6:05                 ` Dave Chinner
2015-04-10  4:43             ` Roman Mamedov
2015-04-10  4:43               ` Roman Mamedov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20150409231035.GI13731@dastard \
    --to=david@fromorbit.com \
    --cc=joe.landman@gmail.com \
    --cc=linux-raid@vger.kernel.org \
    --cc=xfs@oss.sgi.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.