Re: [PATCH 0/5] xfs: quota deadlock fixes

[Eryu Guan <eguan@redhat.com>]

On Wed, Feb 15, 2017 at 10:40:42AM -0500, Brian Foster wrote:
> Hi all,
> 
> This is a collection of several quota related deadlock fixes for
> problems that have been reported to the list recently.
> 
> Patch 1 fixes the low memory quotacheck problem reported by Martin[1].
> Dave is CC'd as he had comments on this particular thread that started a
> discussion, but I hadn't heard anything back since my last response.
> 
> Patch 2 fixes a separate problem I ran into while attempting to
> reproduce Eryu's xfs/305 hang report[2]. 
> 
> Patches 3-5 fix the actual problem reported by Eryu, which is a quotaoff
> deadlock reproduced by xfs/305.
> 
> Further details are included in the individual commit log descriptions.
> Thoughts, reviews, flames appreciated.
> 
> Eryu,
> 
> I've run several hundred iterations of this on your reproducer system
> without reproducing the hang. I have reproduced a reset overnight but
> still haven't been able to grab a stack trace from that occurrence (I'll
> try again today/tonight with better console logging). I suspect this is
> a separate problem (possibly just an ASSERT() failure as this is a DEBUG
> kernel), but I'd appreciate any testing you can run against these
> patches to verify.

Sure, I'll give them a test and report back once I got results. Thanks
for looking into it!

Eryu

> 
> Brian
> 
> [1] http://www.spinics.net/lists/linux-xfs/msg01901.html
> [2] http://www.spinics.net/lists/linux-xfs/msg03835.html
> 
> Brian Foster (5):
>   xfs: bypass dquot reclaim to avoid quotacheck deadlock
>   xfs: allocate quotaoff transactions up front to avoid log deadlock
>   xfs: support ability to wait on new inodes
>   xfs: update ag iterator to support wait on new inodes
>   xfs: wait on new inodes during quotaoff dquot release
> 
>  fs/xfs/xfs_icache.c      | 58 ++++++++++++++++++++++++++++++++++++++++--------
>  fs/xfs/xfs_icache.h      |  8 +++++++
>  fs/xfs/xfs_inode.h       |  4 +++-
>  fs/xfs/xfs_qm.c          | 11 +++++++++
>  fs/xfs/xfs_qm.h          |  1 +
>  fs/xfs/xfs_qm_syscalls.c | 45 +++++++++++++++++++++----------------
>  6 files changed, 98 insertions(+), 29 deletions(-)
> 
> -- 
> 2.7.4
>