Re: [PATCH 0/4] RFC: attempt to remove md deadlocks with metadata without

[Xiao Ni <xni@redhat.com>]

----- Original Message -----
> From: "NeilBrown" <neilb@suse.com>
> To: "Xiao Ni" <xni@redhat.com>
> Cc: linux-raid@vger.kernel.org
> Sent: Tuesday, September 12, 2017 9:49:12 AM
> Subject: [PATCH 0/4] RFC: attempt to remove md deadlocks with metadata without
> 
> Hi,
>  I looked again at the previous patch I posted which tried to mak
>  md_update_sb() safe without taking reconfig_mutex, and realized that
>  it had serious problems, particularly around devices being added or
>  removed while the update was happening.
> 
>  So I decided to try a different approach, which is embodied in these
>  patches.  The md thread is now explicitly allowed to call
>  md_update_sb() while some other thread holds the lock and
>  waits for mddev_suspend() to complete.
> 
>  Please test these and confirm that they still address the problem you
>  found.

Hi Neil

The test have been running for more than 24 hours. The problem doesn't appear.
The patches can fix this bug. 

Best Regards
Xiao
> 
> Thanks,
> NeilBrown
> 
> ---
> 
> NeilBrown (4):
>       md: always hold reconfig_mutex when calling mddev_suspend()
>       md: don't call bitmap_create() while array is quiesced.
>       md: use mddev_suspend/resume instead of ->quiesce()
>       md: allow metadata update while suspending.
> 
> 
>  drivers/md/dm-raid.c     |    5 ++++-
>  drivers/md/md.c          |   45
>  ++++++++++++++++++++++++++++++++-------------
>  drivers/md/md.h          |    6 ++++++
>  drivers/md/raid5-cache.c |    2 ++
>  4 files changed, 44 insertions(+), 14 deletions(-)
> 
> --
> Signature
> 
>