Re: [PATCH 0/2] md: fix fix deadlock while suspending RAID array

From: Simon Guinot
Date: Tue Mar 18 2014 - 11:12:22 EST


On Tue, Mar 11, 2014 at 08:12:08PM +0100, Simon Guinot wrote:
> Hi,
>
> This patch series fixes a deadlock which have been observed while
> updating a RAID array level, using the mdadm --grow command. A full
> description of the issue (hopefully understandable enough) is provided
> by the commit message in the second patch.
>
> Please, let me know if this patches are correct and/or if there is an
> another way (maybe more handy) to solve this deadlock issue.

Hi Neil,

Please, let me know your feedback about this bug and the patches.

Additionally, you will find attached to this email a shell script which
allows to reproduce the deadlock (with most of the configurations).
Basically, this script creates some loopback devices on the top of files
(size 10MB) stored under /tmp. In an infinite loop, the loopback devices
are used to create a RAID1 array and then to migrate this last into a
RAID5 one. At some point, you should hit the deadlock.

Thanks,

Simon

>
> Thanks,
>
> Simon
>
> Simon Guinot (2):
> md: move up mddev locking functions
> md: fix deadlock while suspending RAID array
>
> drivers/md/md.c | 154 ++++++++++++++++++++++++++++++--------------------------
> 1 file changed, 83 insertions(+), 71 deletions(-)
>
> --
> 1.8.5.3
>
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Attachment: md-suspend-deadlock.sh
Description: Bourne shell script

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Description: Digital signature