[dm-devel] [PATCH 2/2] Disable partition scan

[Heinz Mauelshagen]

On Wed, 2009-07-22 at 17:53 +0100, Bryn M. Reeves wrote:
> On Wed, 2009-07-22 at 10:01 +0200, Hannes Reinecke wrote:
> > Worse, it might trigger I/O errors as the partition table might not
> > be accessible (eg for the passive path of a multipath device) or
> > even invalid (eg for RAID0 dmraid).
> 
> Not that it removes the need or motivation for this patch but the case
> of an array partition table being mis-interpreted by the kernel for a
> RAID member device should no longer trigger I/O errors. Kernels since
> 2.6.27 should truncate any over-size partitions to the size of the
> device:
> 
> commit ac0d86f5809598ddcd6bfa0ea8245ccc910e9eac
> Author: Kay Sievers <kay.sievers at vrfy.org>
> Date:   Wed Oct 15 22:04:21 2008 -0700
> 
>     block: sanitize invalid partition table entries
>     
>     We currently follow blindly what the partition table lies about the
>     disk, and let the kernel create block devices which can not be
>     accessed.
>     Trying to identify the device leads to kernel logs full of:
>       sdb: rw=0, want=73392, limit=28800
>       attempt to access beyond end of device
> [snip]
> 
> I've tested this patch with a few dmraid setups that previously spat I/O
> errors whenever something probed a member device. Although this isn't
> exactly a solution it does quiet down the log noise (I'd thought about
> submitting a patch to dmraid to issue a BLKPG_DEL_PARTITION for each
> partition on each member device that it discovers but didn't get around
> to doing anything about it yet).

We've got that in RHEL/Fedora dmraid already with option
"--rm_partitions".

Regards,
Heinz

> 
> Regards,
> Bryn.
> 
> 
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